Shioriho and Ichiro have been together since their school days. They got married two years ago and have been showing the same love and affection as ever, but this summer, Ichiro's affair was discovered. They were also unable to have a child, and Shioriho was in the depths of despair. Meanwhile, Ichiro's father, Tohru, is staying at their house on a business trip to Tokyo. Shioriho is reunited with her father-in-law, who had been kind to her since he was in his hometown, and she is drawn to him. When she realizes that she has been subtly seducing Tohru, she makes up Kokoro and heads to Tohru's house...