What was supposed to be a situation where he was being toyed with turned into a reversal of fortune, driving his sister wild with ecstasy. This is a story of an underdog NTR. After accidentally seeing his best friend's sister masturbating, Yuzuru becomes like a sex toy. Despite his gentle appearance, he has powerful Mach pistons that captivate his best friend's sister！！ The relationship between the two escalates gradually, and the secret affair between the sister and the best friend drowning in pleasure！！
