Young, shy, nerdy Shinichi is spending his summer vacation holed up in his room with the curtains closed. A typical example of the shy, world-weary otaku, we see him building a model kit of a naked female manga character and sending messages on his computer. A few miles away, his rich classmate also appears to have the house to himself (parents are nowhere to be found in this film). But he fills his time dissecting hamsters and pouring glue into his boyfriend's ear. It's Shinichi this rich kid wants in bed next to him, but being more than a little bit obsessed with death and decay, his crush is translated into violent and abusive behaviour. When the two first meet, Shinichi becomes the victim of his twisted admirer's equally twisted gang of thugs, who strip him to his underwear, beat him senseless, burn his genitals with a cigarette butt and destroy his prized manga doll. Several days later, Shinichi finds his tormentor knocking on his door. With the promise that he won't be hurt, Shinichi takes the invitation to come to his classmate's house for dinner. There begins a game of psychological manipulation that takes Shinichi ever closer to breaking point and unearths his own capacities for violence. When the rest of the gang and a number of Shinichi's friends become involved, things quickly spiral down into violent, blood red insanity.