"Onani" means "masturbation. "Masturbation Master Kurosawa." Now, about what do you think this manga will be?
A parody of "Death Note," perhaps?
Story: Kurosawa Kakeru has an interesting daily routine: He goes to a stall in the girls' bathroom and masturbates as he pretends to have violent sex with a random classmate. This is working quite well for him, but one day an antisocial girl discovers him in the stall. They talk, and it turns out that Kurosawa's passion for justice and righteousness is matched by the girl, only she believes that anyone she dislikes deserves to die. Bullied and teased, Kitahara Aya has many people she wants dead.
Soon enough, Kurosawa makes friends with the popular Takigawa Magister, a far cry from his only other friend, the class otaku. They create an odd circle of friends, which manages to drag along the plot for the first half or so. Along the way, random references crop up.
Things can go...
Everybody do the Lelouch!
Whatever you do, don't write down your own name!
Only Kyon himself can best my facepalm... (And, yes, they are dancing the "Hare Hare Yukai.")
And more, all for your viewing pleasure!
While the whole masturbation/cum-on-classmates'-bags-and-worse/borderline-rape aspect is, to be blunt, sick, this is a genuinely funny and original manga. Sure, the quality severely deteriorates near the ending, but the initial shock and comedy is enough to merit an enjoyable read.
Art: Due to sketchy lines and a lack of spot-blacks, the manga looks unfinished, like a rough draft rather than a finished copy. The character designs are pretty generic (the exception would be Nagaoka Keiji), and some even blend together. Just watch out for any female characters. If she isn't Kitahara, she will look like ten other characters in the book. Kurosawa has a lackluster design which makes way for some ace impressions. Backgrounds are functional, but nothing out-of-the-ordinary. It is also to be noted that there isn't much fanservice, especially considering the subject matter.
Characters: (Random: I believe there is a minor character called "Ryuusaki Eru." I SEE WHAT YOU DID THERE.)
Kurosawa Kakeru: In the beginning, he is a complete jerkass. No redeeming qualities at all (unless unintentional epic cosplay abilities count), Kurosawa is the guy you would want to punch in the face. Sure, he's better than Makoto from "School Days" (MUCH better), but it's the same idea. Much to my dismay, he ends up doing a compete 180, which feels forced. However, he has an epiphany somewhere along the way and ends up more likable. Also, he is the only character to develop (it is more like a change-of-heart), but his backstory isn't revealed, of course.
Kitahara Aya: Due mostly to her manipulative, almost suicidal attitude, I never liked her as a character. She almost seems more like Light than Kurosawa; heck, he seems like MISA in her presence! In the ending, she is treated like a joke, which is just uncalled for, especially considering her role. On the other hand, her sexual orientation is played rather subtly for a good amount of the story, which I thought was clever. (She's almost like Theodora from "The Haunting of Hill House.")
Nagaoka Keiji: Other than his role in one of the dumbest and most unbelievable plot twists ever, he is pretty useless. He fills the role of the happy-go-lucky best friend, the otaku with not a care in the world.
Takigawa Magister: Kindhearted, sweet and a caring friend to all, Takigawa is the stereotypical "perfect girl." Is there anything new or original about her? No.
Sugawa Maiko: She's a rough-and-tumble tsundere who bullies Kitahara. Her relationship with Kurosawa is so unbelievable, I was tempted to laugh.
Overall: If you can get past the fact that this manga is revolting, there is a funny parody and some interesting characters. But you're going to have to swim through a lot of cum to get there.