H01173 Imouto Ep 1: A Brother's Secret Pressure

Hikaru spies on his sister Mioto and her boyfriend Hakurou, but Hakurou's sister Akimi catches him and blackmails him into helping her break them up. When Hikaru refuses, she threatens to expose him, and he loses his temper and forces himself on her. The 28-minute episode ends with Hikaru agreeing to cooperate under threat of exposure.