Aku no Hana

The story opens as middle school student Takao Kasuga receives an F on a math test. But he doesn't even seem to notice because he's too engrossed in surreptitiously reading Baudelaire's "The Flowers of Evil". And the day goes downhill from there. In a moment of weakness, he finds and takes home the gym clothes belonging to sweet, pretty Nanako Saeki on whom he has a major crush. Unfortunately for Takao, there's a witness to the theft: Nakamura, who has a huge chip on her shoulder and a sadistic streak.
As the saga unfolds, we see Takao struggling to decide whether to confess or cover up his misdeeds at the same time that he tries to win over the girl of his dreams, and avoid the blackmail attempts of Nakamura, his new ”BFF.”