Tatsuro Udagawa, 27 years old, is a salesman in his sixth year at the company. One night a year ago, his wife Chiaki left a note saying "Goodbye" and left. He has been in a relationship with his colleague Kumiko for three months. On the night his friends celebrated their first anniversary of their separation, he was in the room where he and his wife used to live together, full of memories... One day, when he returned home, he found his estranged wife naked...?! Chiaki was being stalked by an anonymous person. What happened to Chiaki a year ago...?!