It's not that I'm dissatisfied with my wife. However, my Arisa exudes such a seductive charm that I'm so Kokoro that I forget my wife is there. I must not let anyone know about these feelings... But one day, my wife has to leave the house for a company training session, and I ask Arisa to stay over at our house as a watchdog to make sure she doesn't cheat on me. With my wife gone, I'm left alone with Arisa. A night that will shake up reason and instinct begins...