Oddman 11

There're 11 kids in Setsu's school who have special quirks and characteristics, called Oddman. Setsu wanted to date the only male Oddman, Itami, and so she proceeded to challenge all other Oddman since they were his ex-girlfriends. In the process, she made several Oddman fall for her instead. Originally published bimonthly in Comic Megastore Alpha, then Comic Hotmilk (both hentai magazines).