Imouto

Yosugara Hikaru and his sister Mioto have been close since childhood with Sugihara Hakurou and his sister Akimi. Mioto and Hakurou share a mutual affection, while Hikaru secretly harbors feelings for his own sister. While secretly observing Mioto with Hakurou, Hikaru is discovered by Akimi in a compromising act of self-gratification. Akimi, who is in love with her brother Hakurou, demands Hikaru help separate the couple. When Hikaru refuses, Akimi threatens to expose him. In a rage, Hikaru forces himself on Akimi. Overcome with remorse, he later agrees to assist her, provided she keeps his actions confidential.