Shioriho and Ichiro have been dating since their school days. They got married two years ago, and their relationship remained as friendly as ever, but this summer, Ichiro's affair was discovered. His attempts to have a baby with his girlfriend did not go well, and Shiori fell into the depths of despair. At that time, Ichiro's father, Tooru, decided to stay at his house while on a business trip to Tokyo. She reunites with her father-in-law, who has been very good to her since she lived in her hometown, and Shiori becomes attracted to him. When Shiori realizes that he has been subtly seducing Tooru, he makes up his mind and heads to Tooru's house...