Koichi has been married for only five years and already he’s got the seven-year itch. He suffers from a very boring, very ordinary life with his wife Kanako and their daughter. Then one day his neighbor Kimihiko suggests they secretly swap wives. They decide that they will each seduce the other’s wife and explore the wonders of an illicit affair. Koichi isn’t so sure about it at first, but soon finds the deception, fantasies and excitement just the thing to scratch that itch!