"I want to do something naughty with Nagasaki-san." This impossible wish unexpectedly becomes a reality. Her service is different from his wife's; it's sensual and devoted. The two, who meet again by chance in the secluded room of a brothel, become accomplices and have sex. Oral sex in the kitchen while his wife is on the phone next door, and an affair in the bedroom when his wife and child are away. That pleasure becomes the spice that leads Shin and Yukine down an endless labyrinth of pleasure known as "secret adultery."