After getting married, Miyu moved to her husband's family home with her father-in-law. However, as her husband became busier with work, they began to fight over trivial matters. Then her husband went on a week-long business trip. Miyu tried to use this opportunity to come up with a solution to improve their relationship, but it wasn't so easy to come up with one... Seeing Miyu at a loss, her father-in-law decided to teach her the secret to a happy marriage. Miyu was happy, but in exchange for teaching him, he asked her to let him fondle her breasts.