Underskin summary: If sensei won't come, you'll become my partner. In order to get revenge for his cornered-into-suicide father and his dead mother, after 5 years, Akira finally becomes the lover of the congressman who was behind it. But his motive's suspected by the private secretary, Hirose. That night, when he heads toward the hotel to meet the congressman, Hirose's there instead... For revenge, Akira seduces Hirose into bed but, in spite of himself, starts shedding tears. Then he's gently kissed by Hirose, who sees everything...?