4.334 out of 5 from 1,218 votes
Every day after school, the quiet and introverted student Kurosawa goes into the empty girls bathroom and "relieves himself". Besides this extremely odd ritual, Kurosawa also has a thirst for justice and a judgmental attitude towards his classmates. Upon seeing the bullying of an awkward girl in his class by two of the "popular" girls, he decides to bring justice to the bullies the only way he knows how. His plan for revenge goes "just as planned" until met by an unsuspected accomplice.
Takao Kasuga is a lonely boy who spends his days immersed in books to escape his frustration with life. His only source of joy is the beautiful Saeki, who he secretly admires from afar. However, Takao's obsession goes too far one day when, in a moment of emotional folly, he steals the girl's gym clothes and takes them home with him. Worse, his terrible deed is spotted by Sawa Nakamura, a mysterious outcast who sits behind him in class who threatens to reveal the boy's secret unless he promises to engage in a contract with her. At first it seems Sawa just wants some companionship, but soon it becomes clear that this "contract" involves more than mere afternoon chats. In fact, Takao is about to discover just how dangerous his bond with Sawa is and how it threatens to tear everything - his life, his love, and even his sanity - apart.
In both manga, our teenage protagonist is caught doing something pervy/embarassing (stealing a girl's gym clothes, etc.) by a female classmate, who lords it over him, and blackmails him into doing whatever she wants- or else she'll tell everyone his secret. Both are psychologically dark, but while Onani Master is also fairly uplifting, it's unlikely that The Flowers of Evil will be anything but twisted.
It's a bit weird to rec a shoujo manga to a story about masturbation, but hear me out. I find most manga set in high schools to be extremely boring. Most have the same characters acting out the same plots over and over again. Onani Master and Lady Kanoko really impressed me, though. Both are extremely hearfelt with interesting characters, and (aside from Onani Master's frequent parodies) neither feel derivative- you won't find many other manga like them. Though both are about loners learning to make friends and trust others, it never feels like you're reading something you've already seen in some other fluffy high schol drama.
For years, paranoid Satou Tatsuhiro has shut himself away in his apartment for days on end, with barely any social contact whatsoever. Then one day when he answers the door, he is greeted by an older woman and a girl called Misaki, who are going from door-to-door to inform people of the recent social problems of hikikomoris. In a fit of depression about his way of living, Satou decides that the only way to escape his current life cycle is to muster up his courage, face his fears, and go outside to find a job. However, instead of employment, he finds Misaki waiting for him; she intends to make Satou her ‘project' so that he can reconnect with society. Now with the help of his friend Yamazaki and Misaki's evening meetings, will Satou be able to escape his hikikomori lifestyle, or will he simply fall deeper into the clutches of conspiracy and his own demons?
Both contain a similiar comedic tone (With N.H.K possibly edging more on the comedic side) with damaged and confused characters. Both series also contain a very similiar message and the same descent into dark territory. If you like one; you should definately try the other.