The biggest idiot in the world (according to the majority of the cast) and somehow the main protagonist. Though a consistent failure in tests, his one major advantage is that this gives his Summoned Being a special ability to interact with physical objects and dodge attacks by other Beings. Unfortunately, this also causes him to be drafted by various teachers to do their grunt work. Currently lives on his own due to his parents' overseas work and his sister studying in Harvard (though she later came back), and usually has meals consisting of water and condiments due to his habit of spending what little allowance he gets on video games.
Acquired Poison Immunity: Later in the novels Akihisa can survive Himeji's cooking due to spending summer eating his sister Akira's.
Lampshaded by Akihisa. His mom was an even worse cook than Akira OR Himeji. Thus Akihisa ate so much Poison Mushroom for breakfast that he has acquired an immunity to foods that normally can kill people.
All Men Are Perverts: To a much lesser extent than Tsuchiya, but he regularly buys naughty photos from said person as well as owning at least 6 ecchi magazines back at home.
Clueless Chick Magnet: Good God, yes. He may be forgiven for misunderstanding Minami's feelings (given her attitude), but remaining clueless to Mizuki's more overt advances is just ridiculous. Especially since he's had a crush on her since Volume 1.
Starting to avert this now and then, but Status Quo Is God, so he reverts back to being one after just a few days.
Crippling Overspecialization: Graduates from the idiot of all idiots to this as the series goes on, where he can go toe-to-toe with potentially stronger opponents if the match is held using a history subject, particularly Japanese History.
Crouching Moron, Hidden Badass: Slowly turns to this in the light novel and manga, and is hinted to be turning into one at the end of the first anime season. After all, the reason the bracelet broke in the first place was because Akihisa was no longer an "idiot".
Deadly Dodging: His summon has to do this or die because it's so weak breathing on it might even take it down.
Determinator: He might be an idiot, but he'll do his best if he wants to, especially if it involves Mizuki. Down to even studying for an exam just so he can get his grades up for the next summoning battle.
Gibberish of Love: Sometimes a cause of him in getting into trouble with the two girls. One particularly hilarious example is when he got invited to Kirishima's place to study with the gang. He saw Mizuki sporting a ponytail, which caught him by surprise so much he wanted to say "Himeji's so cute today, that my mind is about to explode just looking at you!" He instead said "Himeji's so dead today!"
Hidden Depths: Is a superb cook. Has also shown that he can be fairly smart if he actually puts effort into studying.
Hypocritical Humor: He keeps telling Yuuji to take notice of Shouko already. Despite the fact he can't notice two girls liking him.
I Am Not Right-Handed: Subverted—he believed he could win a Summoned Being battle because nobody knows he's actually left-handed. The result was less than optimal. Funnily enough, the outcome of the battle leads said opponent to underestimate him when they battle six months later in a Japanese History match in Volume 10.
Idiot Hero: Dear God, yes. Though he starts to grow out of his idiocies over time.
If It's You, It's Okay: Apparently thinks homosexuality is wrong (and initially didn't even believe it was real), yet has no problem with confessing to Hideyoshi, buying fanservice-y pictures of him from Kouta, or getting a nosebleed from seeing him topless. He frequently mistakes him as one of the two token girls in class together with Mizuki, although at times he also considers Minami as one. At other times he ignores Hideyoshi's true gender altogether.
In the light novels he does acknowledge that Hideyoshi is a guy (after all, he call the group "four man gang"), but for some reason treats him like a girl anyway. An offhand remark in volume 8 even confirms that, yeah, he feels it is okay if it’s Hideyoshi.
As of Volume 10, Akihisa finally admitted that Hideyoshi is "cool".
Limit Break: His summon has one. He smashes the ground with his wooden sword, breaking the scenery. The enemy summon is then engulfed in light, suspending them and draining their points. He then rushes the enemy, unleashing a flurry of attacks and slashes, sending the target flying.
Meaningful Name: Yoshii means "righteous"/"good"/"good luck" (the first two definitely apply to Akihisa; the latter is the total opposite of his life, unless one counts his Unwanted Harem).
Mundane Utility: His special Summoned Being is like a part of him. His teachers make good use of this—penalty in the form of boring chores.
Nice Guy: Despite being an idiot and sustaining physical abuse from his friends, he generally is this, and even HELPS the same friends who hurt him on a daily basis when they are in need.
Nice Guys Finish Last: He's one of the nicest guys you can meet (depending on who you ask), and because of it, practically everything he has done backfires on him. Although it has its benefits.
The ironic thing is he is oblivious to Mizuki's romantic advances on him despite the fact that he has a crush on her. Instead, he thinks that Mizuki has a crush on Yuuji.
Akihisa is also is the only one of the guys who is oblivious to Kubo's feelings for him.
It should be noted that in the light novels, the possibility of Mizuki and Minami liking him has crossed his mind before. It's just that he usually dismisses it as a delusion, believing they couldn't like someone like him.
Perpetual Poverty: 1/64th cup ramen cuts as lunch, salt water (main course) with sugar water (side dish) meals and cold water showers are some of the miseries caused by how broke he is.
Power Perversion Potential: Since his summon can interact with the real world, it can do some ecchi things like take photos of girls in the baths. Subverted in two ways: first, he has to have a summon field (which means getting a teacher's permission) and, second, if he can summon so can the people he's peeping on, which leads to...pain.
Supreme Chef: He's responsible for preparing the meals in his home. Gourmet-class meals, in fact.
It has been discussed that he could launch a professional career with that sort of talent.
Synchronization: Being the "Probationary Student" ostensibly meaning he inspects how effective punishments are firsthand: his avatar is the only one that can become tangible and he feels whatever it feels.
Too Dumb to Live: All the time. One extreme case is spending most of what little allowance he has on video games instead of food.
The best one has to be he's a member of the FFF, guys who can't get girls and will kill anyone who does including their own. Akihisa also happens to be ranked first rate inquisitor and is the Chick Magnet...Pass the Popcorn.
As of the light novels, he gains a sixth doter in the form of—yes—Hideyoshi.
And Hideyoshi's sister Yuuko too.
Vitriolic Best Buds: With Yuuji—they may hurl insults at each other, fight constantly, and be willing to sacrifice the other to save themselves when the situation isn't that serious, but will instantly join forces once there's real trouble.
Second was when Class A first defeated Class F. He still kept his Brilliant, but Lazy trait, but he's now showing some signs of being a Badass Bookworm. Although it's (supposedly) revealed that Shouko forced him to study or else they'll get married immediately.
Crippling Overspecialization: You want plans and strategies? He's your man. Unfortunately, there's no guarantee that he'll successfully execute his own part when it comes to the studying. He realizes this and goes on to subvert it in time, to the point where his Summoned Being becomes one of the three best fighters statistically in Class F, and one of the better fighters overall.
Declaration of Protection: He won't admit it, but he did this for Shouko. He pulled a Big Damn Heroes moment to save Shouko from 3 boys who tried to bully her after she tried to stop them from writing some vicious lies on his PE clothing; he tried to come up with an excuse not to help, but in the end saves her. Although he tries to pass it off as nothing, Shouko is really touched by that action that she vows to his mother to marry him someday.
Even the Guys Want Him: The Queer's Poll of Volume 10.5 displayed this. He's so popular that his comments were "censored". But since Yuuko is shown to be commenting in Akihisa's poll, Shouko might be responsible for some of these comments as well.
Fiery Redhead: Although he is usually cool and calculating, Yuuji can just as easily be loud and passionate.
Foregone Conclusion: Him marrying Shouko. He'll either concede in the end or be forcefully dragged to the altar. Volume 11 reveals that he wants to do it on his terms, not Shouko's.
Jack of All Stats: To the rest of Class F's main cast, kinda. Once he studied seriously following his first defeat, his grades rival those of Class B, and it is hinted that he could make grades of a Class A Caliber student as well. However, his primary contribution to the class wars is still making up plans and strategizing, and the rest of the students specialize in subjects where they can go toe-to-toe with him, or even potentially surpass him in. And of course, Mizuki Himeji beats him in about every subject, but Yuuji boasts better physical health and stamina and doesn't need to rest as much as her.
Keystone Army: If he's beaten, his class loses the war they're participating in.
Knight in Shining Armor: Played with. It was part of his scheme to get back at two senior jerks who made fun of his class's Maid Cafe in the OVA. However, the first time he did it for Akihisa was played straight.
Played straight with Shouko, with a bit of hesitation at first, when they were young. He hatched up a plan to get three Grade 6 students He did not want Shouko to be involved whatsoever or else face transfer. But he also don't want to fight as he knows he'll lose to three upperclassmen. Cue a Battle in the Center of the Mind with his older self who's taunting him about just making excuses so he can save his own ass. He gets better, and saves Shouko. Too bad it had the effect he didn't absolutely want.
Laser-Guided Karma: Bad things return to him. Lock up Akihisa to use him as a bait? Class F will just kill them both. Laughed at Akihisa for drinking Tabasco? Shouko swaps Akihisa's glass with his.
Marshmallow Hell: From Shouko in Episode 4 of Season 2. She does this to Yuuji to confirm once and for all whether or not he really doesn't find her attractive. Though Yuuji feebly denies he is enjoying it, his avatar leaping for joy (the upgraded Summons speak and reveal their summoners' thoughts and repressed feelings) reveals that Shouko's physical charms are not lost on him.
The Strategist: For Class F. However, when the Second Years have to participate in a joint Summoning Wars with the Third Years, Nemoto acts as a Commander Contrarian to him, locking down his suggestions and essentially preventing him from being heard, with big consequences latter on.
Throw the Dog a Bone: Even if Class F wins a Summoned Being battle, Yuuji declines to penalize the losing class with a room exchange. He has his reasons—as he confided to Akihisa, he doesn't want his classmates to become complacent, at least not until they beat Class A.
Did this again in Volume 9 of the light novels. After they defeated Class C, they finally agreed to switch classrooms with them, but it didn't stop there. Class F promptly challenges Class E to a summoning war soon after, in which they, again, won. What did Yuuji do? Trade their superior Class C facilities with Class E, much to the surprise of the principal.
Tranquil Fury: At the end of Volume 10, Yuuji is so angry at the principal for interfering with Muttsurini's last blow to Shouko (which would have resulted in the victory of Class F against Class A) to the point that he signaled Akihisa to prepare 4 dozen bats with nails and Hideyoshi to prepare a shovel (as the land at the back of the hill is rather hard) while chatting with the principal. Even Akihisa told the principal to go away in order to prevent staining the carpet with blood.
One of the smartest students in Fumizuki, who got stuck in Class F after missing the placement exam due to a freak fever and thus automatically scored a zero. She's the meat shield that keeps Class F afloat in a Summoned Being battle. She has a crush on Akihisa, though he doesn't seem to notice, and tries to win him over with her cooking, but one bite is all it took to cause all her classmates to fear her dishes.
Almighty Janitor: She's got the power of a Class A student, but the poor girl got shoehorned to Class F for skipping out on placement exams.
Minami: Mizuki..what were you planning to do to Aki...
Crippling Overspecialization: Not regarding subjects, but in terms of physical health and stamina, which means she must rest more often than other Class F members. This is a shared weakness with Class A of which she would have landed in had she not fallen ill during the entrance exam.
D-Cup Distress: She complains that her large breasts are heavy and she can't find bras of her size.
Determinator: She will always take one for the team, especially when they're in dire straits. She did take 7 replenishment exams in 5 hours, no breaks, to cover for a recovering Akihisa during a summoning war with Class C.
Does Not Know Her Own Strength: As one of the highest scorers in school, Himeji has a bit of trouble dealing with slightly more delicate tasks like Summoner baseball. Her pitches took out members of both her own team and the opponents'. Adding to this she can't aim well...
Double Standard: Abuse, Female on Male: While she doesn't utilize this as much as Minami, she is often just as willing to punish Akihisa for real or perceived wrongs against her, such as when he tries to get Hideyoshi to strip in a card game, or putting heavy stone blocks on his legs for allegedly trying to sneak a peek into the girl's bathhouse in the second season. If the roles were reversed, Akihisa would probably get thrown in jail pretty quickly.
The Heart: Played with. While she seems to fill this role, Akihisa usually plays the part.
Hypocritical Humour: During Episode 4 of Season 2, she tricks Akihisa into calling his Summon, wanting to know his secrets since the upgraded Summoned beings blurt out the summoner's thoughts, secrets, and repressed feelings, only to act all hurt and betrayed when he dupes her into calling her own Summon using a similar trick.
Innocent Cohabitation: Later in the novel Himeji's parents are stuck in another country for a while and she ends up living with Akihisa and Akira.
Lethal Chef: Her food kills (and she is unaware of it because she doesn't taste it lest she gain weight)note Baka-Tsuki translated one of Himeji's recipes; for those not up on their inorganic chemistry, "King's Water" is called as such because it is one of the few solvents that can dissolve solid gold.
Yamato Nadeshiko: Like with Shouko it's played with. She doesn't have the traditional look but her personality is closer to the trope and she likes cooking for her guy. It might actually taste good if she tested it.
The other female student in Class F. She spent most of her life in Germany, making her bad at reading kanji despite being fairly intelligent. Like Mizuki, she also has a crush on Akihisa—which she expresses by literally crushing him with wrestling moves whenever he misreads her intentions, which is quite often.
A-Cup Angst: She has a complex from her small bust size.
Because You Were Nice to Me: Why does Minami like Akihisa? He asked her to be his friend when she couldn't make any due to the language barrier. But being who he is he asked her in French instead of German.
Clingy Jealous Girl: Doesn't like seeing Akihisa showing interest in any other girl. Even the implication of interest in anyone but her is enough to make her pound him.
Crippling Overspecialization: She does well in math, but not anywhere else. This is justified because the time she spent in Germany made her forget kanji, making every other subject nigh-impossible to understand.
Eloquent In My Native Tongue: The reason why she's in F class is that, having lived in Germany most of her life, she only reads Japanese at an elementary-school level. She can speak Japanese fluently now, though.
Everybody Hates Mathematics: Inverted—math is the only subject she does well. Justified in that spending most of her life in Germany made her forget kanji, making every other subject nigh-impossible to understand.
Expy: A German-Japanese, abrasive Tsundere girl with bad grades due to failure to read kanji yet good with numbers? Oh, and reddish hair and constantly beats down her love interest? Asuka Langley Soryu, is that you?
A student with a talent for acting, whose extremely effeminate looks caused characters and audiences alike to question their sexuality. Everybody frequently mistakes him for a girl despite his insistence to the contrary, is considered by Mizuki and Minami as a rival for Akihisa's affection, occasionally gets confessed to by Akihisa, has a separate space reserved for him in dressing rooms, and keeps getting female roles and costumes from the Drama Department. The only person who considers him a guy is Akihisa's sister Akira—because she didn't expect Akihisa to have any female friends. He has difficulty studying serious subjects, and is pretty much the opposite of his twin sister Yuuko, who happens to be in Class A.
Dude Looks Like a Lady: Incredibly so, to the point that everyone mistakes him for a girl and very little know that he is actually a guy despite him saying so. He even has his own exclusive bathhouse room just because of this.
Easily Forgiven: Due to his appearance and personality, he was the only boy to escape "punishment" by the girls during the Study Camp arc (Volume 3 light novels, Episodes 5 to 7 of Season 2).
Japanese Pronouns: In Japanese, his way of speech is quite antiquated and definitely not what a young person would use. To match with it, he refers to himself with washi, the pronoun old men use—at least in anime.
Meido: He and his sister have worn the uniform before. You decide who looks prettier.
Mr. Fanservice: Though all the Fanservice related to him is clearly meant for male audiences. He's an extremely Bishōnen guy who's often put into cross-dressing outfits against his will, has his own male harem and also has a twin sister. He even lampshades it.
Hideyoshi: Why was my transformation so dramatic?
Naginatas Are Feminine: His avatar's weapon of choice, reflecting on his femininity. His upgraded version, however, ditches it in favor of a katana.
Nice Guy: He's the only guy in class who doesn't try to beat Akihisa up.
Not so Above It All: Deep down, Hideyoshi isn't all that different from the others in class F. He'd occasionally "fit in" with his classmates' antics. One example is blushing over Akihisa's confessions.
Only Sane Man: If it weren't for his appearance and voice, he'd be the nicest guy in Class F!
Running Gag: Never seems to get male clothing (apart from his uniform), and even if he does, its not going to be on him for long.
Scenery Censor: His chest is always covered by something (a towel or a person's arm).
So Beautiful, It's a Curse: He's so beautiful no one believes him to be a guy, and gets confessions from guys just about everyday. invoked Then there's the poem a certain someone wrote to him which kind of gave him nightmares for a while.
The Stoic: Not quite, but most people say he has a good poker face. Quite good considering how many confessions he gets from other guys.
A friend of Akihisa and pervert par excellence who is almost never seen without a camera on hand. Whenever he sees a potential panty/boob shot, he'll squeeze into whatever angle necessary for the best shot, and sells them for some cash. Akihisa seems especially interested whenever he takes a photo of Hideyoshi in a sexy pose. He also turns out to be an excellent athlete, with Health and P.E. grades to rival even those of Class A, but is terrible at all other subjects.
All Men Are Perverts: Takes photos of panty shots or revealing breasts on a regular basis, as well as almost dying by nosebleed if he ever so much as catches a glimpse of it.
Big Damn Heroes: Crashes into the window with Nakamura-sensei straight to where Nemoto is during the match against Class B, which pretty much sealed the deal for the battle.
Crippling Overspecialization: The stand-out example of Class F's students—he's good at health subjects and biology, and nothing else. He is in fact so good at health and physical education that he can easily defeat Shouko, Class A's top student, if they battle in that subject.
Crutch Character: He's the go-to guy if you're in a summoning war and the subject is Health & PE, as he has the highest marks there high enough to surpass the Class A's top student Shouko, possibly for the entire school sans Nakamura-sensei (possibly Takahashi-sensei as well, but it's already given she sucks at basic baseball rules, so...). He's useless everywhere else, however.
Curb-Stomp Battle: He possesses one of the highest, if not the highest, grade in a single subject (Health & PE) for the entire student body, so, naturally, if you fight him in his forte, expect this to happen.
A group consisting of the majority of male students within Class F, often seen wearing dark robes and hodes that hide their features. Since none of them have luck with girls, they formed a pact to hunt down anyone in their class who did. If they find a guy in Class 2-F winning affection from a girl, they will perform an Inquisition upon him. Even Akihisa has donned their robe at times (when he isn't a target).The group has recently enlarged to make up 60% of the 2nd year classes, due to the system the group employs. A heretic is targeted and he is punished by the members, many soon become single after their judgement. Enraged at other heretics who kept their relationships the heretic ends up joining the inquisition and rooting out more heretics; thus continuing the cycle and ever increasing the FFF's numbers.The only named student to be a part of this group is Ryo Sugawa.
An Axe to Grind: To uphold their dateless status, they use, among a list of weapons, axes.
Berserk Button: Mention a girl being nice and prepared to be crucified.
Blatant Lies: A survey displaying the opinions towards a rumor about Akihisa: "...after knowing about this suspicious incident, the F class' students view on the male student suspect are as follows- Death 32%, Deal Death Without Hesitation 25%, A Little Troubled But Death 23%, and Other Forms of Death 20%. As this was an important classmate they were punishing here, the students were severely divided over opinions."
And Now You Must Marry Me: Played for Laughs. She often threatens Yuuji with this, and will tell him if he doesn't do what he said he was going to, such as win a competition, they would get married immediately. It usually works.
Because You Were Nice to Me: A large part of why she likes Yuuji so much is because he was the only person who talked to her like a normal person. Everyone else seemed fearful of her status as a rich girl. And she misinterprets a lot of things Yuuji does for her sake, such as when he beat up those 6th grade kids who were attacking her, and later a Jerk Ass couple who made fun of her while she was in a mock wedding with Yuuji. And his attempts to paint himself as though he's not the right guy for her backfires every time, and only makes her fall more in love with him.
Double Standard: Abuse, Female on Male: Her abuse on Yuuji is one of the most extreme cases of this on record and it's taken to a scary degree. She pokes his eyes until they're sore so he doesn't look at other girls, routinely tazes him, breaks into his house, tries to rape him, and tries to kill himtwice. Once when she thinks that he said "Himeji's more my type than Shouko. And she's got bigger boobs too!" (he didn't). Then when she tries to drown him so she can give him CPR. And not only does anyone not pay it any mind, but their friends actively ship the pair. If their positions were reversed and Yuuji did even one-tenth of the things Shouko does to him, he would be reviled as a monster at the very least.
Heroic BSOD: Was teetering on one for the majority of the latter parts of Volume 11. Koyama's crush on Yuuji was a shock for her, and the fact that she was taking on the brunt of the paperwork did her no favours either.
Rescue Romance: The real reason why Shouko is so obsessed with Yuuji. He pulled a Big Damn Heroes moment to save Shouko from 3 boys who tried to bully her after she tried to stop them from writing some vicious lies on his PE clothing; he tried to come up with an excuse not to help, but in the end saves her. Although he tries to pass it off as nothing, Shouko is really touched by that action that she vows to his mother to marry him someday.
Sugar and Ice Personality: Shouko normally is shown to be very calm and collected and rarely shows strong emotions to others. Her cute side is reserved to Yuuji, but she usually expresses it in a rather scary way.
Supreme Chef: She trained herself in every way to be the perfect house wife to Yuuji, including this.
A green-haired girl and a bit of a troublemaker who might be Kouta's equal in terms of Health and P.E., except she adds that she has "practical" experience in that area.
Ascended Extra/Recurring Extra: Depending on which part of the story, but she plays a role here or there giving minor hints to the arc. But most of the time she just likes to tease and watch the guys get into trouble.
A calm, collected boy who usually sticks to a tight schedule and has very good grades as a result. However, after a small misunderstanding, he thought Akihisa was trying to hit on him, and now happens to have a crush on Akihisa.
Worthy Opponent: Seems to consider Akihisa one later on in the series. A good majority of her effort in the third summoning war between A class and F class is devoted to trying to take him out early on; calling him the "first key affecting the war".
A minor Class A student who was Akihisa's opponent in Physics during the Test Summon War, where she easily defeats him.
Curbstomp Battle: Delivered one to Akihisa when they faced each other during the Test Summon Wars. Their battle in Volume 10 does not end this way.
Underestimating Badassery: Not during the Test Summon Wars. Rather, this hapens in Volume 10 where her remembrance of Akihisa's defeat at her hands and his laughable revelation led her to underestimate him when she went to cut him off as he was racing to stop Kubo. The match subject was Japanese History which is Akihisa's speciality, and he dealt enough damage to her to the point where another Class F student could barely finish her off.
You Shall Not Pass: To Akihisa in Volume 10, when he went to fight Kubo a second time. She fails.
A cunning schemer and Class Representative of Class B who's willing to cheat his way to victory and good grades. He tried forming an alliance with Class C, only to be defeated by Yuuji and his own plan, forcing the poor guy to get dressed in female clothing and get photographed by Yuuji as leverage to force his class into fighting Class A.
Humiliation Conga: Not only is he defeated by 2-C — or, to be more exact, Out-Gambitted by Yuuji — but he was also forced by Yuuji to get photographed wearing female clothing as blackmail material to force him and 2-B to fight 2-A.
The Load: His decision to be Commander Contrarian and lock down Yuuji in any way possible is one of the chief reasons why Volume 11 ends with the Third Years sporting the advantage in the joint summoning wars.
Freudian Excuse: Sort of hinted at in the light novels. She declares that her father should be the first one to disappear before all other men. Akihisa then notes that she looked like she "recalled something repulsive" and wondered if something might have happened.
Mad Love: She constantly harasses Minami, attacks anyone who gets to close to her, resorts to blackmail, and even does things that would be grounds for criminal charges if not a restraining order in a more realistic setting on a regular basis.
Two recurring third-year students who attempt to ruin Class F's Cultural Festival.
Butt Monkey: Nothing good happens to them. Special mention to Shunpei, thanks to the fact that "Aki-chan" stuck "her" bra on him to make it seem like he's a pervert and the bra remained on him for the rest of his appearances.
The Worf Effect: Why Akihisa and Yuuji were able to handily beat students who are not only their seniors, but Class A material.
Voiced by: Saori Yumiba (JP) and Martha Harms (EN)
The member of Tea Ceremony Club and Gymnastics Club. First appears during the Ghost Outbreak Arc to defeat Kouta (and the rest of the boys except Hideyoshi, Akihisa and Yuji. She is also Yuka's sempai in the Tea Ceremony Club.
A hardcore master of discipline who possesses great physical ability and serves as the current homeroom teacher of 2-F. He is the one who drags students off to remedial lessons if their Being gets KO'd in battle. Whatever the time, place, number of students or even relevance to school, he will pop up and drag them all back for those lessons.
Meaningful Nickname: Ironman literally is tough as iron as he can shrug off Aki's summon hitting like nothing.
Non-Giving-Up School Guy: He invokes this trope by showing up out of the blue anywhere an avatar has "died", whether in a school battle, or even while taking a bath at a bathhouse, to take them to remedial classroom.
Akihisa's 23-year-old sister with a bust that rivals Mizuki's. She studied at Harvard, but comes back to Japan later in the story to look after Akihisa. Considering some of her dialogue, it's possible that she has a brother complex or is just very good at teasing him in order to get him to do better. Unlike her brother, she's very smart, but bad at cooking.
Innocent Fanservice Girl: When she's first introduced (in the anime anyway), she shows up in a bathrobe. She then explains to Akihisa that she was getting hot and sweaty on the train to visit him, so changed clothing on the train, while there were men in the same car as her. They suffered some minor injuries from her clothing change.
Jerk with a Heart of Gold: She often berates Akihisa for using his (often failed) attempts at trying to get a good grade as a good enough goal to strive for. But aside from her other tendencies, she does genuinely care about him and tries to look out for him, such as letting him live alone so that he could concentrate on school rather than worry about her.