Kangoku Gakuen (監獄学園, literally Prison School) is a seinenecchi series by Akira Hiramoto (of Me And The Devil Blues fame)Hachimitsu private academy was an elite all-girls boarding highschool known for its strict rules. The school recently turned co-ed and has started by admitting five boys. There are over thousand female students in the academy, which at first seemed exciting to the boys but none of the female students want to talk to them. Which is for good reason as unbeknownst to the five, the underground student council has forbidden female students to associate with the boys.The only one of the five whose has any luck talking to girls is Kiyoshi. He drops his eraser in class, which has a sumo wrestler design on it and when he picks it up it's spotted by his crush Chiyo, who like Kiyoshi is a huge sumo wrestling fan. After class the two talk about sumo wrestling and begin a budding friendship. Chiyo even invites him to watch a sumo match on the weekends with her.Unfortunately those plans may have to be put on hold. The boys decide to peep on the girls bath and are caught. Their punishment is one month in the school's prison with their prison guards being the three members of the underground student council who seem intent on making sure the boys have a hellish month.
Kangoku Gakuen provide examples of:
Absurdly Powerful Student Council: The main purpose of the underground student council is to enforce the school's rules against male/female interaction on school grounds. To do that they're allowed to lock up any student caught breaking those rules in the school's fully functional prison, that they run with almost no supervision from the school facility. A lot of the abuse they put can put their prisoners through violate school rules but lack of supervision makes it easy to get away with it.
Strangely, the school has another student council as well, the "Aboveground" Student Council. They're just a normal student council, and aren't even relevant to the plot until they take over duties of their underground counterparts, who have to serve prison time.
Abusively Sexy Woman: Meiko punishes the boys a lot and provides most of the fanservice for the series. There are numerous cases of her doing both at the same time like when she whips Kiyoshi in the butt and Gakuto's groin, while sitting on Gakuto's face. For at least first couple days of their sentence all of the boys actually like being abused by her because she's attractive, and they get to see her panties while she disciplines them.
Acrofatic: Andre engages in some impressive acrobatics during his masochist withdraw induced madness.
All Men Are Perverts: All the recurring males characters are huge perverts. The boys who are only in this mess because they wanted to peep in the girls' bath and the chairman of the school who has an ass fetish.
Despite most of their stay at the school being hellish the boys pledge to remain at the school because at the end of the year school trip there's going to be a wet t-shirt contest.
Always Someone Better: For a while is seemed like Meiko and Hana where the two strongest fighters in the school. Then Risa is introduced, outfights Meiko, and even manages to block simultaneous kicks from both if them.
Ass Shove: On two separate occasions Kiyoshi has gotten a pointy object lodged up his ass.
This is subverted with Gakuto. After a string of accidents (purposefully done) that ended with him pulling down Mari's skirt. Gakuto goes to Meiko to atone. She puts on a glove, and pulls an object from a drawer that's mosaiced out. It's later reveal that it was just hair clippers. Gakuto's atonement is he had his hair shaved.
Kiyoshi's date with Chiyo goes well until he decides to go to the restroom. While he's gone Chiyo accidentally spills water on his bag. Thinking he has a cell phone in it, she opens the bag to get the phone out only to find her school uniform. Kiyoshi had no idea that the uniform he had stolen for breaking out was hers. When he comes back, she calls him disgusting and runs off.
Bait the Dog: The first time Hana is introduced to the boys she comes off as cheerful and friendly and she asks them to collect four leaf clovers for a good cause. However it doesn't take long for the boys to find out that she's just as cruel as Meiko when she kicks Shingo in the head for not finding any.
After Kiyoshi's breakout, Mari decides that the boys are too dangerous to stay in the school and comes up with a scheme, OBE (operation boy's expulsion), that would manipulate the rest of the boys into getting in trouble and breaking out two more times. That way the school facility would see the boys as a danger to the school and the chairman wouldn't be able to come to the boys defense when they become candidates for expulsion. Other than a few hitches, like Kiyoshi stopping Jo from stabbing Mari and Anzu getting a change of heart and helping Shingo, it works.
They take advantage of the fact that Shingo was the most anxious to be released from prison. So they offer in a deal in private that if he gets information on friends he gets certain privileges, one of which allows him to go outside the prison, provided he comes back before his curfew or it would count as a breakout. There he meets Anzu, who unbeknownst to him, is tasked with getting close to him, later going on a movie date with him and messing with the time on his watch so that he's late coming back.
They take advantage of Andre extreme masochism and obsession with Meiko by not punishing him and have Meiko wear more modest clothes. Denied of punishment and fanservice he starts to wither away and become desperate. Later on they lead him outside alone and Meiko who's just outside the barbwire fence promises him punishment if he comes to her. This prompt him to charge through the fence, made possible since the USC weakening the wires, and since he's outside the prison it's considered another breakout.
Kiyoshi pulls one on Meiko. The boys give her the withdrawal forms she gave them along with a petition to the chairman seeing if he can do something about their coming expulsion. They beg Meiko to deliver the petition. Meiko agrees to this but on her way there tears up the petition, in anger of Gakuto not finishing the food she made him. Still, much to the surprise of the USC, the chairman request to see the boys in private. Kiyoshi wrote his message to the Chairman on his withdrawal form because he knew Meiko wouldn't check the forms after tearing up the petition.
Keito has proven herself to be a very skilled manipulator. All of the characters she's targeting know she's up to no good but still fall for her traps, most of which require minimal effort from her part.
She takes advantage of Meiko's eagerness to please Mari to severely damage the USC's reputation. Keito has Risa take Meiko to an area of the school next to some trees, one of which contains a nest, home to three baby crows belonging to Mari. Meiko is tasked with cleaning up the branches and leaves in the area and she also gets a sweet potato she can roast when she's done. Meiko enthusiastically gathers the leaves and branches to starts a fire for roasting the potato, which plays right in Keito's hands. Keito had the fuel poured on the area beforehand so Meiko's small fire quickly grows uncontrollable and spreads right into the tree with the crows nest. Kiyoshi, Chiyo, and Mari come to her aid but by the time the fire is put out the tree and the nest are burnt, apparently killing the baby crows who couldn't escape because they can't fly yet. Unfortunately, since no one was around to see how the fire got started all the students that came to the scene assume that Meiko intentionally killed the baby crows for food, and the rest of the students find out about the incident from the school newspaper, which Keito wrote and printed out before the fire even started. Meiko doesn't have an explanation for how the fire got started so she thinks it's her fault the crows are dead which severe traumatizes her. The USC get their prison time extended for a week because Mari went away from her work zone, which still counts as a breakout. As if all that wasn't bad enough, Keito uses the aftermath of the situation to announce to the students in the area her proposal to disband the USC. Considering the events that had occurred even before this incident, it certainly seems like a tempting proposition.
She orchestrates one on Chiyo too. When a group of Keito's lackeys threaten to beat up her friend unless Chiyo strips for blackmail pictures, Chiyo surprises both them and the readers by instead handing them their asses with her sumo skills. Unfortunately that was exactly what Keito had planned on, having brought the Chairman to see Chiyo beat up a bunch of students from too far away to be able to hear the earlier context. Cue one of the biggest wham moments in the manga as Chiyo of all people is sentenced to prison time.
The Beastmaster: Mari has a flock of crows under her control that she's able to use for things like surveillance to enforce her rule about not talking to the boys and to attack people.
Be a Whore to Get Your Man: Chiyo attempts to tart herself up when she misinterprets her sister as having stolen Kiyoshi's affections from her.
Berserk Button: While Jo is usually quiet and reserved he becomes extremely violent if someone harms his ants. He tried to beat up Andre when the latter accidentally knocked over his ant farm.
Blackmail: Shingo wants to stop being the USC spy after what they did to Jo, but Meiko warns him that if he quits then she'll tell the rest of the boys that he's been selling them out.
And later Hana does it to Kiyoshi with a picture of their make out.
And both Mari and Kiyoshi again with suggestive footage of them taken during a Suck Out the Poison situation that Keito engineered for that very purpose.
The Blind Leading the Blind: Neither Kiyoshi nor Shingo have much experience with romance but Kiyoshi did kiss Hana, granted it was under unusual circumstances. After some begging from Shingo, he tells Shingo the events that led up to the kiss. Shingo to tries replicate the situation in his karaoke date with Anzu. He cuts off the top portion of a water bottle, takes off his pants, puts the bottle over his penis and walks towards Anzu. All of this causes a very startled Anzu to give Shingo a severe beating, which Kiyoshi told Shingo would happen since Hana beat him up as well. Unlike Hana though, who kissed Kiyoshi afterward (as part of her revenge), Anzu simply smashes a TV over his head and runs away.
Blind Without 'Em: Chiyo's vision is apparently so bad that in chapter 2, when she takes off her contacts for the bath she mistakes Kiyoshi for her friend Mayumi.
Boobs of Steel: Meiko has the largest breasts in the series, and is frighteningly strong, quite possibly the strongest girl in school. She broke a restroom stall door with one kick, can subdue Hana, and is able to beat all five boys in arm wrestling in a row.
Break the Haughty: In elementary school Keito, along with her posse, constantly bullied Meiko. That stopped shortly after Mari transferred to the school and became friends with Meiko. When Keito tried to make fun of Meiko for her sarashi tearing apart Mari embarrassed her in front of the entire class by calling her a "base woman". Then her attempt to get revenge completely backfired when she, along with her posse and some boys, tried to force Mari to beg for her forgiveness. It almost worked but while Meiko was too meek to stand up for herself, seeing her friend being bullied was another matter. Meiko went berserk, beat up the boys, scared off Keito's posse and would have beat up Keito too had Mari not intervened.
Broken Pedestal: In the present story, Mari has very little respect for the chairman though the flashback chapters reveal that she used to admire him. It's unexplained what exactly caused a rift in their relationship but it's heavily implied to be because of the chairman's perverted habits.
The USC used to be admired by most of the student body, even having a few fangirls. However, their reputation took a massive hit when it's revealed to the entire school what they did to the boys in prison and that they'll be the serving time themselves for it. To make matters worse the Aboveground Student Council is trying to get them in more trouble to lower their popularity even further.
Bullying a Dragon: Andre, as a prison guard, is uncharacteristically sadistic towards Meiko, who is one of the strongest students in school and there isn't much stopping her from putting him in a lot of pain when she gets out. Which is exactly want a masochist like Andre wants. He's hoping that the crueler he is towards her the more vicious her revenge will be when she gets out.
Butt Monkey: Gakuto is frequently on the receiving end on a lot of slapstick. He gets punished the most of all the boys by the USC. In a few cases he doesn't even do anything to deserve being punished. For the sake of getting his Guan Yu action figure he craps his pants and gets in enough trouble to get his long hair shaved. The sad part is that later on he ends up having to smash the figure.
Hana whenever she's alone with Kiyoshi. She's been caught urinating outside, urinated on, faints when an erect penis touches between her legs, and her last attempt at getting revenge on Kiyoshi gave the boys an opportunity to get the evidence that brings down the USC.
The Cavalry: The Laundryman, as well as being a Chekhov's Gunman, manages to get Shingo back to school in time, after he's been sabotaged. Shingo still doesn't get back into prison in time though.
There's a few panels showing some newspapers in Keito's bag. Chiyo gets a glance at them as she's greeting Keito but doesn't think much of it at the time. Later on however, it becomes one of the reasons why she's sure that the fire that apparently killed the three baby crows wasn't an accident. She's able to recall that the headlines of the paper talked about a bonfire and since Keito printed out the paper before the fire had occurred she realises that Keito must have planed for it.
That single panel of Hana's phone falling out of her pocket when Kiyoshi made her faint by tongue kissing her? Turns out the camera was on at the time and captured the whole thing. Cue blackmail from Hana much later when the two are alone again.
Clock Discrepancy: During Shingo's movie date with Anzu she sets his watch thirty minutes behind so he would be late getting back to school. By the time she tells him he has only five minutes to get back.
Clothing Damage: Invoked by Mari, who gives Meiko a suffocatingly tight but more modest school uniform. Meiko thinks this is her actual punishment for the incident with Gakuto's action figure but later when trying to goad Andre to go through the prison's fence, the uniform gives out and tears which excites Andre enough to charge through the fence just as Mari planned.
And her catsuit and her panties, all on separate occasions. A pattern emerges.
Clingy Costume: Meiko wears an extremely tight Cat Suit to patrol the school grounds at night. Later she take it off to use the restroom only for the zipper to get stuck. She ends up having to tear the zipper off and use the toilet nude.
Co-Dragons: Meiko and Hana serve as such for Mari. They spend the most time with the boys since they're the prison's guards.
Contrived Clumsiness: Gakuto accidentally pulls down Mari's skirt, but later it's revealed that he did it on purpose. He knew that he would have to atone for doing something like that and for his atonement he asks Meiko to shave off his long hair. He then gives his hair to Kiyoshi to make a wig for his disguise.
Covert Pervert: The chairman of the school, despite his stern elderly appearance, has a fetish for women's butts, something he tries to hide from his daughter Mari and fails at miserably on multiple occasions.
A drooling Keito clearly enjoys watching Kiyoshi and Mari'sSuck Out the Poison incident far beyond the pleasures of revenge.
Cruel Mercy: After the incident with Gakuto's action figure Meiko begs Mari to punish her. Mari refuses to do so and tells Meiko it's not her fault but she says it in a backhanded way by saying it's her fault for trusting Meiko to handle the situation. Despite Mari's merciful response Meiko notes that by her not punishing her she can't atoned for her actions so in a way Mari is still punishing her.
Custom Uniform of Sexy: Meiko wears her uniform with most of her shirt unbuttoned showing off her cleavage and then some, an extremely small skirt that reveals her panties anytime she bends her legs, thighhigh stockings and stiletto heeled boots.
Cut Apart: When Kiyoshi accidentally urinates on Hana, the next panel is a close-up of liquid falling into someone's mouth. The panel after that pans out to reveal that it's Meiko drinking water from a tap.
Dangerously Short Skirt: Meiko wears a hip-length skirt which exposes her panties almost every time she bends over.
After OBE is complete the USC destroys all documents of the plan. However, they're unaware that the files they deleted on their computers can be recovered. Knowing of this, the boys plan to recover the files from the computer in the warden's room and give them to the chairman to prove that the USC framed them.
Some clues help Chiyo deduce that the apparent death of the three baby crows wasn't an accident. One of which is that only part of the tree they were in was burnt and in such a way that lead directly to where the nest was. Unfortunately, the Aboveground Student Council, in covering their tracks, cut down and disposed of the tree before Chiyo could show Kiyoshi.
Determinator: When it comes to getting his Guan Yu action figure no price is too high for Gakuto. He willingly craps his pants in the one class the boys have with female students, ruining any chances he has to get a girlfriend. Later on, he purposefully gets in trouble to get his long hair cut so Kiyoshi can use the hair as a wig.
Disguised in Drag: Kiyoshi's backup breakout plan involved him walking out the front of school wearing a girls uniform and a wig made from Gakuto's hair. It works so well he even managed to fool Mari on his way out.
Distracted by the Sexy: Twice the boys gawk at female students when they're supposed to be working, and both times Meiko punishes them for it.
During Kiyoshi's arm wrestling rematch with Meiko he spots her nipple due to her being unaware of having a nip slip. He's so enamored by the sight, it puts him in a daze, where he doesn't even realize Meiko had already won the match.
Disproportionate Retribution: The entire peeping Tom incident leads to the five boys being forced to commit slave labour, live in a prison, get physically and mentally abused to the point of bleeding, and plotted against for expulsion.
Dojikko: Mitsuko, who seems to have the universe conspire toward her panties falling on the floor.
Dominatrix: Risa tries to be Andre's Dom since Meiko, after the fire incident, is incapable of hurting him. She's having little success since she not as wicked as Meiko so all of her abuse ends up being too soft for Andre.
Everyone Calls Him Barkeep: The Chairman's full name has not been revealed and the only reason why we know his last name is because we know the full names of his daughters.
Similarly, while we know Mari's and Meiko's full name every character but Chiyo, who calls Mari "big sister" and Meiko "Meiko-chan", refers to them as the president and vice president.
Excrement Statement: In the nurses room Hana forces Kiyoshi to lie on stomach on a bed so she can urinate on him as payback . She doesn't get a chance to do it since she has to go under the bed with him to hide from Chiyo who just walked in.
Face of a Thug: Shingo is noted to have the look of a delinquent. Mostly likely because of his blonde slicked back hair.
Everything about Risa's early characterisation seems to indicate a personality that fully fits her thug-like appearance but Andre at least thinks she's a lot nicer at heart. Too nice for his tastes in fact.
The Faceless: We are never shown the top portion of Jo's face since he almost always has on his hoodie and in the rare instances that he doesn't have it on there's always something else distorting his face, like suds when he's bathing or bandages covering his head and Scary Shiny Glasses when he was disguised as Gakuto.
Faking the Dead: Risa reveals to Kiyosi that fire that burned the tree with the crows nest didn't kill the baby crows because the Aboveground Student Council took them out and into a cage before the fire happened.
Familial Reveal: Despite not getting caught getting out of and back into the school, the USC still discover that Kiyoshi broke out and he's confronted by Mari who has evidence of it. During the date, unaware that Kiyoshi wasn't allowed to leave the school on weekends, Chiyo took pictures of them together with her cellphone and sent them to her older sister and father. Who, much to Kiyoshi's horror, are revealed to be Mari and the chairman.
Finger Muzzle: Andre quiets Risa, who's at a loss of how to be a good dom for him, by putting his finger on her lips and reminding her that she as a dom she should not ask questions or seek answers, she should just order.
Forced to Watch: Gakuto is tasked with watching Mari and Hana as they work but when Mari's pants tear, exposing her panties Gakuto tries look away. Risa, however, uses her kendo stick to force him to keep his eyes on them no matter what because she wants to condition him not to have any respect for the female prisoners.
Form-Fitting Wardrobe: The female uniform the USC have to wear are impossibly form fitting. Chapter 89 opens with at illustration of Meiko wearing one and it looks painted on as it conforms to her breasts, nipples and labia. It has the same effect on Mari and Hana though to a lesser degree since they're not as voluptuous. Keito states that Mitsuko "accidentally" got the wrong sizes for them but if anything the uniforms are actually an exact fit.
Meiko's catsuit, naturally.
Freak Out: The fire that apparently killed the three baby crows severely traumatizes Meiko because she, and the rest of the school, is tricked into believing that it was her fault. As a result of the trauma, her personality regresses back to the submissive personality she had in elementary school.
Her personality change causes Andre to lose his sanity due to his dependency on her abuse. He can't deal with a submissive Meiko that refuses to hurt him. He spends most of the chapters after that being unresponsive, neglecting his hygiene and muttering to himself.
Gainaxing: Most which comes from Meiko since her clothes don't exactly keep her large breasts in. It's no surprise that there are a lot instances of her breasts bouncing all over the place.
Bizarrely subverted later on when Kiyoshi gets put in prison again and has to wear the same thing.
Girl Next Door: Chiyo, Kiyoshi's crush who sits in front of him in class. She's kind, friendly, the first girl to want to talk to any of the boys, and like Kiyoshi, is a huge fan of sumo-wrestling. Despite being the school chairman's daughter she is very down to earth and despite her sister's antagonistic relationship with Kiyoshi and the boys, she helps the latter when she can.
Gonk: All the characters in the series are normal looking with the exception of Andre who is large, has an egg shaped body, a face that is way too small for the rest of his head, and over-sized Budha-like earlobes.
Great Escape: Different from most cases of this trope Kiyoshi's breakout plan involves him sneaking out and back into the prison for his date with Chiyo. While he's gone Gakuto could tell Meiko that he's in the restroom, and if she goes to check he can use the remote for his speakers he placed in the stall to play the clip of him crapping his pants to make it seem like Kiyoshi is in the stall.
Heel-Face Turn: Anzu, after hearing how Shingo sold out his friends to spend time with her. She quickly tells him the trap that the USC have set up for him and later joins Chiyo in helping the boys get out of being expelled.
Hellhole Prison: The prison cells are very dirty, the boys have to do a lot of hard labor and Meiko and Hana punish them liberally. Despite all this Kiyoshi notes that it's only taken a few days for the boys to get used to their prison life. They still take their classes, though through a monitor, and they get the same food as the rest of the students. Unfortunately, it goes back to being a Hellhole Prison after Kiyoshi's breakout as the student council are more strict on the boys and manipulate the boys into getting themselves in trouble.
Gakuto is devastated when he and Kiyoshi discover that someone had fixed the hole in the wall Kiyoshi had made, ruining their break out plan and for Gakuto this means he pooped his pants for nothing. When Kiyoshi hears him crying during bedtime it gives him the resolve to come up with a new plan.
Kiyoshi, after his date with Chiyo. The date ends badly with Chiyo thinking he's a creep when she finds her uniform in his bag, the USC finds out he broke out, and he got everyone's prison time extended by a month so his friends hate him. He's easily convinced by Mari to fill out a withdrawal form, which he almost does until Chiyo stops him.
After the boys' first attempt at recovering the documents of OBE fails Kiyoshi's notes that they're not even sad about it, just broken. They continue their routine just waiting for their inevitable expulsion. The sole exception is Gakuto, who Kiyoshi describes as being not just broken, but destroyed. Specifically, he rambles constantly about impossible escape plans.
Hit Me, Dammit!: After falling for the USC's trap and revealing how he sold his friends out Shingo offers them a chance to punch him as payback. They all decline except for Kiyoshi, who takes him up on his offer since Shingo punched him for his breakout but ends up simply giving him a light tap on the shoulder, at first anyway. (see Restrained Revenge)
Hope Spot: After Anzu tells him about the USC's trap for him Shingo runs to the school with only minutes left until he's late and it's considered another breakout. He nearly gets hit by a car on his way. Fortunately the driver is nice enough to drive him the rest of the way. He arrives in front of the prison with 30 seconds to open the door and get inside. Unfortunately, Mari seemed to have planned for a situation like this and had the rest of the boys change the door to a sliding one while he was away. Shingo is unable to open the door in time with gives the USC their third breakout.
Gakuto is able to sneak back in the recreation room after Meiko defeats all the boys so they assume that he was able to recover the files about OBE. Unfortunately, he informs them that he was only able to install the program to recover the files. When he heard Andre screaming during his match he quickly rushed back. At that point the boys' expulsions seemed to be inevitable.
How the Mighty Have Fallen: The USC go from running the school prison to being inmates. Their guards are members of the real student council, who are just as abusive to them as they were to the boys. To add injury to insult, some of the boys have even been recruited to help out with their punishment.
Hypocrisy Nod: During his date with Anzu. Shingo notices two boys throwing sand at another boy. When he goes to confront them about it the two boys tell him they're throwing sand at the third boy for breaking their rule about not talking to girls. Shingo yells at them saying that even the third boy broke their rule they should forgive him because he's their friend. After the boys leave Shingo is sadden by the realization of how hypocritical that was coming from him since he's yet to forgive Kiyoshi.
I Ate What?: Mari faints after it's revealed that the plastic blade that was in her food was found on the floor of a restroom.
I Kiss Your Foot: During the boys first day in prison Meiko orders Andre to lick her boots for shielding Jo from one of her beatings. She relents when Kiyoshi points out that she's taking things too far. Oddly enough Andre gets angry at Kiyoshi since he actually likes being bullied by Meiko.
Ironic Echo: There's a lot emphasis on the panel where Keito calls Mari a "base woman" for her hypocrisy (see Moral Myopia). The irony of that insult is revealed in a later chapter that's a flashback. When the two were in elementary school Mari had used the very same insult on Keito in front of their entire class for making fun of Meiko in a childish manner.
In-Series Nickname: All five boys have "codenames" that they're referred as almost exclusively.
Kiyoshi Fujino: "Kiyoshi"
Shingo Wakamoto: "Shingo"
Takehito Morokuzu: "Gakuto"
Jouji Nezo: "Jo"
Reiji Andou: "Andre"
Insane Troll Logic: Kiyoshi's answer to the chairman about why asses are better than boobs is crazy but correct, at least to the chairman. When man walked on all fours all he could see were women's asses, but as man evolved, the ass was no longer in front view and boobs took their place. So in the end, boobs are just fake asses and if one has to choose between the original and a fake, they should obviously choose the original.
I Thought That Was: Anzu gets two tickets for her and Shingo to watch The Grapes of Wrath which is a very subdued film but the title causes the two to mistake it for something akin to Attack of the Killer Tomatoes!. At least Shingo did, Anzu knew exactly what the movie was and used it to bore Shingo asleep to mess with his sense of time so he'd be late for his curfew.
Laser-Guided Karma: While Meiko gets Gakuto's action figure broken (though definitely not on the terms she wanted) the figure ends up getting the last laugh. Shingo, who is unaware of what happened since he was just coming back from running errands, comes back and identifies a piece of the figure as the plastic blade he found on the restroom floor and gave to Meiko. The same blade Meiko accidentally threw in food she made for Mari and ended up in Mari's mouth. Meiko tried to hide where blade was found out of fear of Mari's reaction but thanks to Shingo, Mari finds out and faints at the revelation.
Leave Behind a Pistol: The USC convince Kiyoshi to leave the school by filling out a withdrawal form. Mari notes that rumors about Kiyoshi crossdressing have already spread so if he stays in at the school he'll mostly be treated like a freak.
Meiko gives the boys withdrawal forms to fill out so they don't have to continue waiting for the school staff to decide on their expulsion, which at the time seemed inevitable.
Little Miss Badass: Hana is the shortest and least endowed character. She's also a black belt in Karate and can beat the living daylights out of the boys.
After a group of Keito's lackeys try to force her into a Shameful Strip, it turns out that Chiyo's knowledge of Sumo isn't restricted to simply appreciating it.
Loophole Abuse: The USC sentence Kiyoshi with expulsion for his breakout. However, as noted by Meiko, the USC have no authority to expel students but students can request to be withdrawn from the school by filling out a withdrawal form. So Mari tries to prod Kiyoshi into filling one out. He almost does until Chiyo stops him.
Love Interest Traitor: Anzu was working for the USC the all along. Her mission was to get close to Shingo, invite him to watch a movie with her and set his watch thirty minutes behind so he'd be late coming back to school which would count as a breakout. She gets a change of heart at the last minute when Shingo reveals all he's done to be with her.
Major Injury Underreaction: When Kiyoshi gets stabbed in the butt for the second time he downplayed the severity of his injury and simply blames it on his hemorrhoids despite clearly having a piece of a branch lodged up his profusely bleeding ass.
Make It Look Like an Accident: The fire that supposedly killed Mari's baby crows was made to look like Meiko accidentally let it get out of control when it was really Keito who had fuel poured on the area and tree with the crow's nest.
Male Gaze: There are numerous shots and close-ups of breasts, butts, and crotches. Especially with Meiko, who has a lot of panels with her dialogue or inner monologues also being centered on those areas.
Marshmallow Heaven: When Chiyo cradles Kiyoshi's head to protect him from Meiko she ends up pressing his head against her breasts. She lets go after she realizes what she's doing. Later Kiyoshi notes how wonderful the experience was and it adds to his resolve not to withdraw from the school.
When she finds that he's been on porn sites she retracts the boys' weekend privileges, which is why Kiyoshi decided to break out for his date with Chiyo.
When he accidentally spills his collection of dirty pictures in front of her she informs him that she's going to start becoming more strict on the boys.
Later, despite his best effort to hide his "ass" ergonomic mousepad, she spots it and in her inner-monologue she decides to intensify her plans to get the boys expelled.
Mistaken for Gay: Kiyoshi and Gakuto get mistaken as couple by the rest of the boys. They kept their breakout plan to themselves so from the perspective of the other boys the two are spending an unusual amount of time together.
Shingo walks in on the two in the showers and sees what he thinks are the two having sex, really it was just Gakuto kneeling down to get his bar of soap and Kiyoshi helping him up when he slipped. The rest of the boys blame Kiyoshi's "hemorrhoids" and Gakuto's crapping his pants on them having sex.
When Kiyoshi tells Gakuto about his second breakout plan he proclaims that he's going to become a girl, meaning he's going to disguise himself as a female student to sneak out from the front of the school, but the other three interpret it as he's going to be the bottom in their relationship.
And later Mitsuko quite understandably mistakes Gakuto and Jo for a couple after seeing them role-play as such, ironically in an effort by Gakuto to become more comfortable with her interests.
Moral Myopia: Mari knows Keito will try to provoke bad behavior from the USC in order to get their prison sentences extended, she even calls out Keito on it, telling her that she wouldn't put it past her to do something so low. Keito denies the accusation (even though it's exactly what she's doing) and also reminds Mari that what she's accusing her of and looking down on her for is the exact same thing she did to the boys. The look of stunned silence on Mari's face seems to indicate that she realizes Keito has a point.
Ms. Fanservice: Despite the setting being a school with over 1000 female students and more than half the cast being female, the vast majority of the fanservice comes from Meiko, mainly in the form of Male Gaze. The chapters where she's not around tend to have little to no fanservice.
Noodle Incident: An incident twenty years before the present story led to the Underground Student Council imposing harsh punishment for any student caught socializing with males. The specifics of that incident are never explained.
Nosebleed: Hana gets so overwhelmed when she forces Kiyoshi to make out with her that she gets a nosebleed and faints.
One-Sided Arm-Wrestling: All five boys challenge Meiko to arm wrestling matches and all but Andre last only a couple of seconds. She even throws Jo to the wall.
Operation Blank: The USC devise a scheme to get the boys expelled, Operation Boys Expulsion, or as they like to refer to it, OBE.
Overly Nervous Flop Sweat: Aside from sweating a lot when she works out, Meiko breaks out in constant sweat attacks when she thinks things aren't coming along as they should be, or when she's failed the President.
Pet the Dog: While Meiko has been the cruelest of the USC to the boys, she is the only one to do something nice for them by offering them a last meal the day before their expulsion should have been decided on.
Piggy Bank: Risa, of all people, has a piggy bank. She breaks it to get enough money to buy a domantrix outfit to wear for Andre. Fortunately, the shopkeeper at the store is moved by her passion to be a dom and gives her an old outfit for free.
Playing Nice for Now: Hana does not want anyone knowing about her urinating outside. The only person that knows is Kiyoshi who spotted her doing so. While she treats him like a she treats the other boys, she constantly looks for opportunities for the two to be alone she can get revenge on him.
Kiyoshi lied to Chiyo that he could leave school on the weekend and broke out to go on a date with her. Unfortunately, when she finds her school uniform in his backpack she assumes the worst and runs out on the date before he could explain anything. Later after she hears that Kiyoshi could be expelled she decides it wasn't fair of her to not allow Kiyoshi to explain himself. After he does, the two mend their relationship.
After Chiyo stumbles on documents for OBE, she tries to alert Kiyoshi by arranging the pieces of her board game to spell out a warning. As Meiko escorts the boys back to their cells Kiyoshi spots the warning. However, he read it from the wrong angle so the message was gibberish to him. When he later writes the message for Gakuto to see, the latter is able to figure out that it's a warning but by the time they realise this, OBE is too far ahead for them to stop it.
Kiyoshi and Mari have enormous difficulty in communicating to their allies outside of the prison the supplies they require to break out, something that ends up costing them several days of valuable preparation time.
Porn Stash: The chairman has a collection of photos of women's butts. After it's seen by Mari twice he decides to bury it outside the school. It takes him to two tries get rid of it for good. The second time he uses cement so he won't be able to dig them back up like last time.
Of course even with his memorial photos gone he still has the porn sites he frequents and his ass mouse pad.
Potty Emergency: Invoked by Hana when she forces Kiyoshi to drink tea that will make him want to use the restroom. That way they can be alone and she can get her payback. Kiyoshi is aware of this and tries to hold it in so he doesn't have to ask for permission to use the restroom. Unfortunately, Gakuto sees him trembling and asks for him.
Prim and Proper Bun: Meiko has her hair in a bun at all times. She's shown to be very strict and formal, and she does not hesitate to use her whips on the boys for any kind of misbehavior.
Princess Curls: The Aboveground Student Council President Keito introduced in Volume 9.
Raging Stiffie: Kiyoshi gets ones after Hana forces him under a bed in the nurse's room to hide from Chiyo who just walked in to see Kiyoshi. Kiyoshi, who's extremely close to Hana gets an erection, despite his best efforts not to. It ends up touching Hana right between her legs which causes her to faint.
Subverted with Gakuto during the sports Festival. The female students think he has a boner, when it's really just the speakers that came with his mp3 player.
A later gag features Kiyoshi frequently being forced to hide these during his second prison term with Meiko and Mari. The fact that all three are wearing such tight revealing clothing doesn't help.
Reasonable Authority Figure: The chairman, though he lets his daughter handle disciplining the boys, he urges her to be as lenient as possible. She usually disregards that request. After the USC tricks the boys into breaking out enough times to get expelled, he's still reluctant to expel them and tries to give them enough time to stop their expulsions.
After Kiyoshi finds out that the apparent deaths of the three baby crows that Chiyo is devastated by was caused by the Aboveground Student Council, he immediately goes to recruit the rest of the boys in an attempt to find evidence against them. Considering how strong their friendship is it should have been easy to get them to join his cause. Unfortunately, none of them are even willing to listen to what he has to say.
Shingo is too angry to hear him out because his date with Anzu was ruined by Kiyoshi's advice.
He tries to appeal to Gakuto's love of the Romance of the Three Kingdoms by asking Gakuto to become his "Zhuge Liang". He means a strategist (Zhuge Liang was a formidable one) but to Gakuto, who has been researching yaoi involving Zhuge Liang, it comes across as Kiyoshi wanting to sleep with him. Gakuto runs away because because he doesn't feel worthy.
Andre can't listen to anyone since he's severely depressed over Meiko's personality change.
After Kiyoshi gets caught and sent to prison again, they find out about the conspiracy from Chiyo but they still refuse to help. Jo and Shingo refuse to take part in anything that would inadvertently help the USC, Gakuto doesn't want to go against the Aboveground Student Council since his love interest, Mistuko, is a member and Andre is still a mental wreck.
Restrained Revenge: Played straight and averted after Plan OBE is done. Shingo offers the boys a chance to hit him and Kiyoshi takes him up on his offer as payback for Shingo hitting him last time. However, Kiyoshi simply taps him on the shoulder, telling him that all of them have made mistakes and they all forgive him. At least until Shingo tells the boys about how got to see Anzu's bra and a nip slip. Then Kiyoshi punches him hard and the rest of the boys beat the crap out of him out of jealously. They do forgive him right after though.
Keito's primary motivation is revenge against Mari for humiliating her in elementary school even though she was the bully at the time (see Break the Haughty).
Hana wants revenge on Kiyoshi for seeing her pee outside. Then double revenge for both that and what happened when her previous attempt at revenge went wrong. Then triple revenge when that backfired. You get the idea.
Sacred First Kiss: Kiyoshi get his first kiss stolen by Hana in the warden's room. Her reason is to deny Kiyoshi the opportunity to share his first kiss with his crush. Like most of her attempts at revenge this one ends up backfiring on her. Kiyoshi realizes from the stiffness of her kiss that she's extremely innocent when it comes to romance and overwhelms her by turning the kiss into a make out session which causes her to faint.
Sadistic Choice: Poor Gakuto has found himself between a rock and a hard place twice.
For part of their breakout plan to work, Kiyoshi and Gakuto need an mp3 of someone taking a crap to make it seem like Kiyoshi's using the restroom while he's actually on his date with Chiyo. The only chance they have get the mp3 during their prison sentence is the time that they have a combined class with female students in the computer lab where they will have computer and internet access. Unfortunately, they can't find any such mp3 on the web and the only way they're getting one is to use the microphone on Gakuto's headphones to record one of themselves crapping their pants. Kiyoshi can't do it since Chiyo's also in the class so Gakuto decides to take the bullet. Kiyoshi begs him not to, since doing so will assuredly ruin any chances of him getting a girlfriend but Gakuto reasons that not being able to buy the Guan Yu action figure which only comes out once every four years is worse than not being able to get a girlfriend for three years and does it anyway as Kiyoshi sheds Manly Tears.
After finding Gakuto's Guan Yu action figure, the next day Meiko has the boys lines up outside, brings out the toy and slowly starts breaking it in front of them. She won't stop until one of them claims the toy. This leaves Gakuto with two options. Watch as his prized possession is slowly broken in front him or claim the toy, which, since Meiko knew the only day the toy was sold was on the day Kiyoshi broke out, would also mean admitting to have aided Kiyoshi and get the boy's jail time extended even further.
He decides to Take a Third Option by diving for the toy, looking at it one last time and smashing it to pieces to prove to Meiko it doesn't belong to him.
Sanity Slippage: Hana was Cute and Psycho to begin with, but the terrible things that happen to her over the course of the story do not do wonders for her sanity.
Andre basically loses his mind when denied punishment from the vice president.
Screw the Rules, I Have Connections!: After abusing their powers and almost getting five students expelled one would think the USC would get a harsher punishment than just house arrest. Keito confronts the chairman about it. When she accuses him of bending school policy for the USC because his daughter is a member he denies the accusation and agrees to her proposal to have the USC serve a prison sentence under the watch of the Aboveground Student Council.
Screw the Rules, I Make Them!: The USC are supposed to enforce the school rules but they don't have any issues breaking numerous of them in their attempt to get the boys expelled.
Secret Test of Character: When Mari first tells Meiko about her intention to get the boys expelled she dubs her scheme "plan OBE". Since the O in OBE stands for operation "plan" and "operation" are overlapping, Meiko knows this but can't decide whether to correct Mari. Mari ends up correcting herself. Later on she discusses OBE with Hana and calls it plan OBE again. Hana instantly corrects her. This time it was test as Mari wanted to see if Hana still had a sharp mind after her leave of absence.
Serious Business: The only way the chairman will consider giving the boys the time they need to prove their innocence is if they answer this question "What do you like more, Tits or Asses?". Considering the chairman has an ass fetish the answer is obvious, explaining why is the difficult part.
The series main concept revolves around this really. It's only a simple school but the concept of the prison is treated completely seriously by all involved.
Andre develops an entire business model "Andreconomics" around investing abuse onto the Vice President for greater punishment later.
Shared Family Quirks: Chiyo, Mari and the Chairman have each stated on separate occasions an odd belief that anyone who loves sumo/crows/asses cannot be a bad person.
Shy Bladder: In a restroom stall Hana demands Kiyoshi urinate while she watches as payback for Kiyoshi seeing her urinating outside. Kiyoshi tells her he can't with her watching so she tries to physically force him, only to end up slipping on the floor and for Kiyoshi to unintentionally relieve himself on her.
Slap-Slap-Kiss: What Kiyoshi's confrontation with Hana in the guard room eventually comes down to.
Smells Sexy: Unsurprisingly, a small and dirty prison with just five guys smells pretty bad. Later on though, Kiyoshi gets sent to prison again, but this time he's locked in with Mari and Meiko. He notes that the prison is now "A lockup filled with the pleasant scent of women".
Spanner in the Works: Kiyoshi and Gakuto's first break out plan depended on a hole Kiyoshi had spent days making in one of the walls surrounding the prison. Unfortunately, the chairman, who was burying his dirty pictures for the second time using cement happens to find the hole and fills it up himself, unknowingly ruining the two former's plans.
Spiteful Spit: Meiko has spit on Gakuto and Andre on multiple occasions to punish them. Andre, being a masochist, licked her spit the first time.
Stanford Prison Experiment: Keito references the actual Stanford prison experiment as her reason for recruiting Andre and Gakuto as prison guards to watch over the USC. At first the two, especially Gakuto, were uncomfortable bossing around the USC but by the second day, with a little prodding by Keito who gives the two prison guard uniforms, they're just as cruel as the USC were to them.
The Stool Pigeon: Shingo becomes one for the USC after Kiyoshi's failed breakout. In exchange for getting information about his friends he gets good food, the USC no longer punishes him, and he gets to leave school under the guise that he's running errands for the USC.
Stop, or I Shoot Myself!: Chiyo threatens Mari that if she ever tries to get Kiyoshi to quit school again she'll turn in her withdrawal form and leave the school too.
Suck Out the Poison: Kiyoshi and Mari are both forced to do this for each other in some very awkward places when locked in a bathroom with a bunch of snakes. The worst part is that they weren't even venomous. The Aboveground Student Council had put them there to film this very action for blackmail purposes.
Sweetheart Sipping: Hana forces Kiyoshi to share a soda with her when her first order of blackmail is to take some new blackmail pictures that aren't quite so unflattering.
Sympathy for the Devil: In spite of everything Hana puts him through, Kiyoshi apologizes to her for playing with her feelings to get the evidence needed to take down the USC. Her response is to kick him so hard she breaks his arm and almost punches him in the face while he's down (Mari takes the hit). Yet even after that he still feels sorry for her, stating that he deserved to get his arm broken. Part of the reason the USC was able to get off so lightly was because he refused to press charges against Hana.
A Taste Of Their Own Medicine: After their plot to expel the boys is revealed, the Aboveground Student Council usurps the Underground Student Council's authority and subjects the USC to the same treatment they gave the boys. It doesn't help that Keito, the Aboveground Student Council's president, hates Mari and Meiko, and is even more of a manipulative bitch than Mari was. It gets to the point where Kiyoshi gets thrown back in prison trying to help them out.
Too Kinky to Torture : Andre loves being abused by women, especially if the abuse is from Meiko. He willingly takes punishment for some of the boys in a few cases, and slowly withers away when he stops receiving punishment.
Villainous Breakdown: After the USC plot to expel the boys is revealed to the chairman, Hana softly asks Kiyoshi if he had unlocked the back entrance of the prison while she was unconscious, which was, ironically, the result of a kiss she had forced on him. Kiyoshi regretfully confirms this saying he took advantage of the weakness in her heart and apologizes. In spite of his apology Hana charges at him in a furious rage, kicking him so hard she breaks the arm he used to block the kick. She almost punches him in the face while he's on the floor but ends up punching Mari instead. Mari had jumped in to shield Kiyoshi as anymore abuse to him in front of the chairman would have gotten Hana in more trouble.
Wardrobe Malfunction: Meiko, on multiple occasions, wears clothes that are way too tight for her curvaceous figure and end up giving out and tearing at the most inopportune moments.
Mari gives her a suffocatingly tight but more modest school uniform. Meiko thinks this is her actual punishment for the incident with Gakuto's action figure but later, when trying to goad Andre to go through the prison's fence, the uniform gives out and tears which excites Andre enough to charge through the fence just as Mari planned.
The back of the pants of her prison uniform tear as she's trying to quickly complete her task of digging a large hole.
In a flashback chapter, Meiko's Sarashi audibly tears when she stands up too fast in class to answer a teacher's question.
Gakuto antagonizes the cleaning man as a distraction so Kiyoshi can sneak in the female laundry room and steal a female uniform.
The USC has Shingo strike up a conversation with Jo to move him away from his ants so Mari's crows can attack them.
All the boys challenge Meiko to arm wrestling matches to distract her while Gakuto steals her keys and goes to the wardens room to recover the files for OBE.
What the Hell, Hero?: Kiyoshi gets punched and yelled at by Shingo for getting the boys' sentence extended by a month for selfishly breaking out to go on a date with Chiyo.
Kiyoshi is initially very angry when he finds out that Andre and Gakuto have become prison guards as he feels that even if they're still angry at the USC, becoming guards to bully them is taking things way too far. The two calm him down by insuring him that they're only doing it to help the Aboveground Student Council and have no intention of abusing their powers, though that ends up being the case anyway (see Stanford Prison Experiment).
Workout Fanservice: Any time Meiko works out since she usually does her workouts in her revealing school uniform, her large breasts tend to flop around a lot, she sweats so much it makes her clothes transparent and as with most of her panels, the focus tends to be on her breasts and crotch.
Wrongful Accusation Insurance: Kiyoshi mentions that although Gakuto broke out of prison and Chiyo assisted him, neither of them will receive any punishment since their efforts lead to the reveal of wrongdoing by the USC.
Your Eyes Can Deceive You: The main reason why Meiko struggles with her arm wrestling match with Andre is because she can't stop staring at his long lone nipple hair. She then realize it's not a distraction if she can't see it, closes her eyes and quickly wins.