Keiichi, a husband, was in charge of large investments at a foreign fund. His colleague, Oki, was both his best friend and rival. However, one day, Keiichi suffered a huge loss and was cornered. Oki proposed a game to Keiichi. He would seduce Keiichi's wife, Mayu, and if she went along with it, Oki would win, but if she didn't, he would give up the deal... Keiichi was absolutely confident. That Mayu loved him. And as the game began, Oki skillfully confused Mayu's Kokoro and stole her away...