Seiji Hasumi, 32, teaches English at a private high school in a suburb of Tokyo. A graduate of Harvard University, he worked for a time at a major U.S. investment bank. But despite the stellar résumé, he has two diametrically opposed sides to his character. On the one hand, he plays the role of dedicated teacher and is popular with his students for his learner-friendly teaching methods; on the other, he has secretly bugged the school building in order to gather information on the students and has been fixing things so that his favorite students—with emphasis on the pretty girls—will be in his 11th-grade homeroom. Shortly after the start of the school year in April, he rescues Yasuhara from sexual harassment by the gym teacher, who holds a shoplifting incident over her head, and makes her his own lover. He discovers that art teacher Kume, the pampered son of a wealthy family, is having an affair with a male student, and blackmails him for the use of his luxury apartment and Porche on his assignations with Yasuhara. Then, on the last day of classes before the start of summer vacation in July, he kills a male student who seems to be catching on to his schemes; thinking Yasuhara knows, he decides to make it look like a suicide and kill her, too. Near the end of summer vacation, with the school's annual Cultural Day slated for September 1 fast approaching, the entire class gathers at school for an all-night session to prepare the spook house they've planned. Hasumi takes the opportunity to push Yasuhara off the roof, but his plan goes awry when he's spotted by a student on his way back down. He kills the girl; then, in order to cover his tracks and implicate a colleague, he begins blasting away with a shotgun at all 40 students present for the all-nighter. A serial-killer story that ratchets the mayhem up several notches beyond Bret Easton Ellis's American Psycho.