Takayuki has been married for five years, but he and his wife have been living a boring married life without any children. One day, he witnesses his neighbor, Asahi, having an affair. Asahi, who noticed what was happening, invites Takayuki into his house and forces him into a relationship as payment for keeping quiet. Takayuki becomes addicted to Asahi's sexual techniques and goes on a trip to Hakone at Asahi's invitation, but the trip is actually a trap set by someone. What will happen to their relationship in the future?