Kana and Masato have been married for four years. They begin to see parts of each other that they couldn't see before, and their quarrels over trivial things only increase. At that time, I was invited to the house of Tsubasa, my girlfriend's classmate from ●school, whom I met again at her class reunion. Tsubasa, who was plain when she was a student, has become so beautiful that it is hard to recognize her...And soon, the whole couple is invited to Tsubasa's house, and Masato learns that the secret to Tsubasa and his wife's marital harmony is a husband and wife swap. listen…