The brothers Rizu and Kyoya fight whenever they meet. They don’t get along very well and always start arguing even in the presence of their friends. One day, Rizu comes home running to avoid the rain and runs into Kyoya at the entrance. Rizu gets angry, but she freezes when she looks at Kyoya’s spectacular shirtless body. He has a pretty muscular body, just the way she likes it. When Rizu notices that she is looking at her brother lasciviously, she tries to avoid the topic and run away, but she gets into an accident and hurts her ankle. Kyoya takes her to her room and treats her wound, but she begins to become aware that her sister is very attractive and that she has entered her room for the first time. Kyoya tries to put these thoughts to rest and leaves the room before things get heated, but Rizu asks him for a massage. Kyoya reluctantly agrees but decides to accept because he feels guilty that she had her accident, but then he realizes, while he is giving her the massage, that her sister is completely the type of girl he likes. .