The fate of the world rests in the vaginas of three "fruits", who conveniently happen to be school girls. If these "fruits" are harvested, aka deflowered, the world will be destroyed. Fuck the world anyway, let's tear up some hymens!
Yukito, being the ambitious fucker he is, applies to be a domestic servant at a mansion. The landlady tells him he can only get the job if he masturbates in front of her. He gets the job.