A college student otaku male started living alone due to his advancement in education. His sister, envious of him, began frequently entering and exiting his room. One day, she bumped into her brother's friend. Like her brother, he was an introvert, and she seduced him with a panty shot, enjoying his reaction. The sister found it amusing to tease the shy older man, and her actions escalated over time, even destroying her brother's friendship. The sister, awakened to her abnormal fetish, began to involve her brother as well, seeking psychological pleasure…
