Her older brother is an otaku and somewhat of a recluse, and he often gets cocky and insults in FPS games. One day, because of this, she picks a fight with the son of a big-time yakuza boss, who ends up showing up at her house. There, Hinori is the one who takes her brother's place. She is made to embrace him in front of him, and even serves him during meals, and her heart is torn to shreds... But her young, sensitive body accepts the action, climaxing over and over again... and she becomes submissive... Where will this sister, who is succumbing to pleasure, and her brother, who is venting his anger at her, end up?