At a high school in Kobata City there exist 11 individuals called Oddmen, ten girls and one boy who all possess certain unusual physical abnormalities or unshakable mental compulsions, whether it's being a lifetime nudist, a sex-crazed Cat Girl, an intimidating sadist or an anthropomorphic dog, canine instincts and all. Seemingly normal schoolgirl Setsu is interested in going out with Itami, the sole male Oddman, but after learning that he's exes with 9 of the other Oddmen and currently in a relationship with the last (who just so happens to be his sister), she's convinced to defeat all the other Oddmen to earn the right to go out with him, just like in that movie. As she defeats the Oddmen, though, they each end up forming a circle of friends around her, until she ends up accidentally creating her own all-girl harem.
Created by Dowman Sayman, the creator of The Voynich Hotel, the manga is effectively Scott Pilgrim as a gender-flipped raunchy lesbian sex comedy. Sexual and Toilet Humor humor abound, as well as plenty of bizarre situational comedy, though these are occasionally juxtaposed with some surprisingly heartfelt moments and even moments of horror.
Oddman 11 provides examples of:
- Accidental Harem: Setsu builds up a growing harem of Oddmen over the course of the series, and while she considers them all good friends, she treats the advances of some of them with casual aloofness. She does end up giving mixed signals on occasion, though, being very supportive of Shiraishi's various sexy outfits and instantly agreeing to Ika-chan's out-of-the-blue marriage proposal without first hearing why she wants to get married.
- Accidental Pervert: When tasked to find one of Shiraishi's rare golden hairs by Tatari, Setsu invites her to a pool as an excuse to get her in a skimpy swimsuit and then proceeds to carefully examine every inch of her body, completely unaware of just how perverted it makes her look.
- Acquired Poison Immunity: Both Setsu and the other Oddmen eventually get used to Fujou's BO enough to tolerate being around her.
- Ass Shove: Setsu defeats Seigi by sneaking up behind her and giving her the "kanchou" butt poke, which startles her badly enough for Setsu to knock her down. Setsu spanks her repeatedly, then tops everything off by shoving her arm elbow-deep up Seigi's butt.
- Big Bad: Sister Itami, Oddman 2, is the sadistic and controlling girlfriend of Brother Itami whom protagonist Sakamata Setsu must defeat to win the love of Brother Itami.
- Big Damn Heroes: Inuta, Shiraishi and Nuida don't arrive in time to prevent Setsu from getting decapitated by Seigi, but they're able to at least distract Seigi and get Setsu's body to Comic Zin in time to keep her alive.
- Censor Steam: Played for laughs. When Setsu shows her breasts to Nuida and Inuta in the dorm bath, they're covered up by both steam and a Lens Flare Censor that not even the actual characters can see through.
- Clumsy Copyright Censorship: Played for laughs in a fourth wall-breaking way. When Chouko goes on a rant about five-star review systems, she uses Brand X substitutions for Amazon and Yelp so that she doesn't have to do the usual asterisk censoring for the real names, only for Setsu to point them out (asterisks and all) and render the effort moot.
- Curse: Personality-based Oddmen quirks seem to be treated as some sort of curse, compelling their respective Oddmen to behave a certain way even against their own best interests. For example, Nuida regularly implies that she's not a nudist by choice, and being able to wear a hair ribbon given to her by brother Itami is a huge shock to her. Also, Shiraishi is compelled to do whatever her partner wants, which at one point leads to a gangbang involving more than 30 guys.
- Curb-Stomp Battle: The two times Setsu's conflicts with the Oddmen have turned violent, she's been on the receiving end of one of these.
- Cute Monster Girl: Most of the Oddmen fall into this. So far there's a Cat Girl, an anthropomorphic dog, an octopus/squid girl, a Cyclops, a Horned Humanoid, a shapeshifting Humanoid Abomination and a Plant Person.
- Darkest Hour: Chapters 43-45. Setsu is nearly killed by Seigi, leaving her in a coma, and when sister Itami goes on a Journey to the Center of the Mind, Setsu seems to have given up on her quest to defeat and befriend all the Oddmen because of her. Thankfully, Itami is able to change her mind. However, Comic Zin has closed down, meaning that future attempts to get Setsu's Healing Factor to kick in will be much, much harder, if not outright impossible.
- Defeat Means Friendship: Each Oddman that Setsu defeats joins her growing circle of friends, while a few such as Fujou, Shiraishi and Nuida become full-on love interests.
- The Dreaded: Shiraishi tells Setsu to watch out for Numbers 7 and 11. Both of them turn out to be the strongest of the Oddmen, with Seigi being the strongest, to the point of nearly killing Setsu.
- Dynamic Entry: When Setsu catches some boys making fun of Nuida, she butts in with a Rider Kick while disguised as the town mascot.
- Establishing Character Moment: A manga-wide example. The very first page is Setsu walking in on sister Itami pissing on her brother's face, setting the tone for the rest of the series.
- Everyone Is Bi: All of the Oddmen have dated brother Itami at some point, and a large number of them have also fallen for Setsu as the story progresses.
- Fetch Quest: Tatami's challenge is to gather three items from the other Oddmen. It's taken many chapters just for Setsu to get two of them, and due to the last one coming from sister Itami, she's put it on the back burner.
- The Ghost: Number 6 has yet to be revealed outside of a panel with silhouettes of all the Oddmen aside from the Itami siblings. Multiple characters in that panel have since gone through a design change before their official debut, so it's not even a good indicator of what she'll look like.
- Ghost Story: On two instances, characters try to tell scary stories, only for it to get completely derailed.
- Gotta Kill 'Em All: A non-fatal, usually non-violent version, as Setsu's goal is to get brother Itami's exes to admit defeat in some way or another.
- Identical Panel Gag: One chapter has Shiraishi repeatedly sending Inuta out to fetch various items, all using the exact same panel.
- Imagine Spot: When starting Tatari's Fetch Quest, Setsu decides to start with Shiraishi's golden hair, since she knows she'll cooperate. Cue Smash Cut to a fictional Shiraishi.Setsu: I mean, if I ask her she'll probably cooperate with me.
Shiraishi: Okay, sure! I'll trade you for your virginity!
Ika-chan: ...is what she's going to say and you know it.
Setsu: Hm, I guess you're right...
- Inelegant Blubbering: Chouko is prone to this. Shiraishi and Nuida also succumb to this after getting drunk after Setsu becomes Chouko's girlfriend.
- Insane Troll Logic: The entire premise of the story is that Setsu decides to defeat brother Itami's exes in order to go out with him. Brother Itami insists at the very start that it isn't necessary, and indeed the entire battle hasn't really brought them any closer, but both Setsu and the other Oddmen insist on going through with it because that's what happened in "that movie."
- It's the Journey That Counts: Brother Itami insists at the very start that Setsu defeating his exes is completely unnecessary, but by then Setsu and eventually all the other Oddmen commit themselves to it. Indeed, over time Setsu seems more interested in defeating and befriending the Oddmen than actually going out with brother Itami specifically.
- Journey to the Center of the Mind: After Setsu is rendered comatose after her encounter with Seigi, sister Itami is somehow able to enter her mind and snap her out of it.
- Lovable Sex Maniac: Shiraishi's Oddman quirk makes her the reigning champion of this trope, but some of Setsu's other love interests like Fujou frequently delve into this trope towards Setsu. Noticably averted with Chouko, whose perversions are treated as more creepy than endearing.
- Mix-and-Match Critters: During the culture festival, Setsu puts together a costume of Core-man, the town mascot, who's an amalgamation of everything Kobata City is famous for. This results in a bizarre abomination with the head of a donkey, the arms of a bat, body of a salmon, and taro for legs.
- Mood Whiplash: Chapter 25 is all about this, from Chouko having nobody left in her life after Kiko ceases to exist and Setsu promising to do anything to make up for it, only for Chouko to ask to watch her pee, and then throw herself off the school roof when Setsu says no and ending up in a coma, to Setsu tearfully promising to let Chouko watch her pee when she wakes up.
- Pool Scene: At one point Setsu tries to invite Shiraishi to a pool so that she'll have a chance to steal a golden hair off her body. Shiraishi's completely uninterested until she discovers that the pool in question is the infamous "That Pool".
- Previously on : Played for laughs when one chapter ends with Sister Itami forcing Setsu to endure getting spanked three times with a deer skin glove (which is established as being incredibly painful), getting one over with before the end of the chapter. The next chapter starts with Itami getting in a second one and claiming that it's the first because she was just recapping the original one.
- Running Gag:
- Chapter 16 has Shiraishi repeatedly sending Inuta to go fetch various things, using the exact same panel each time.
- Tatari eventually talks about when she went out with Brother Itami, and how the first time they had sex was in the "Sailboat tea-grinding mill" position. Cue "Sailbot tea-grinding mill" being repeated several times in a row, across two chapters.
- School Festival: A large chunk of the manga revolves around the school culture festival.
- Shout-Out: Numerous. From the aforemented Scott Pilgrim, to Mobile Suit Zeta Gundam, Gantz, RoboCop and Studio Shaft.
- Suicide as Comedy: After Kiko ceases to exist because of Chouko's feelings for Setsu, Setsu promises while they're sitting on top of the school building to do anything to make up for it...except let Chouko watch her take a piss. Chouko responds by immediately throwing herself off the roof. Thankfully, she survives.
- Toilet Humor: One chapter revolves around Setsu taking Inuta out for a walk. Due to Inuta being compelled to follow her dog instincts, she ends up insisting on going to the bathroom outside. Hilarity Ensues.
- Visual Pun: When Setsu is talking with cyclops Tatari over the phone, Tatari's avatar is shown to be a Z'Gok, a Cyber Cyclops.
- Voodoo Doll: At one point Shiraishi and Fujou challenge each other to a Pop-Up Pirate game with a custom figure of Setsu. Setsu, all the way at Comiket, is able to feel where they jab the toy swords as they play.
- You Are Number 6: Each Oddman, along with their normal name, has a number designation and a title. Number 11 in particular was often referred to by number until she finally made an on-screen appearance.
- Yuri Genre: The series is a Yuri version of Scott Pilgrim, in which a high school girl does battle against the titular Oddmen to gain the affection of the one male Oddman but ends up attracting the female Oddmen as well.