"Concentrate... on the obscene acts you're doing with me." Tomomi, a philosophy graduate student, has a one-sided crush on Professor Takatsuki, who is famous for being sadistic. On the way back from a drinking party, Tomomi was helped by Takatsuki when she got entangled in a male student. "This must be a dream that sensei is kind," while thinking like that, she was pampered by him. When she woke up the next morning, she was in Takatsuki's room. To Tomomi, who aspires to pursue her philosophy and worries about her future, Takatsuki proposed - "You, marry me."