After marrying his childhood friend, his wife, Mizuki, ends up living with her partner's parents. On the surface, she had a happy married life, but there was one problem. It is her brother-in-law, Kazuo, who is a recluse. Worried about Kazuo, who was also her old friend, Mizuki makes up her mind and heads to his room. There, she learns that she is confused about the reason for her withdrawal, but she tells him that she wants to help somehow... Kazuo furious