Fujishima Ryouto

He has two older brothers who are married, he has a good relationship with his brothers, he lives with them and their wives. He has sex with lonely housewives under the pretense of wife association. One day he got a text from a new lonely housewife. While waiting he ends up find out the housewife he meets is no other then his sister-in-law Shizuka. He also learns that both of his sisters-in-laws are having affairs behind his brothers' backs. Angered he decides to blackmail them at the same time.