Shinyuu no Imouto ga Kannou Shousetsu no Model ni Natte Kurerurashii

A high school student writes erotic novels using his best friend's younger sister as a model. She discovers his work online and confronts him. After he apologizes for using her image without consent, she responds by suggesting he observe her in revealing ways. She proposes various suggestive scenarios, including examining her feet, reading explicit material aloud, and engaging in role-play. The story explores the resulting comedic and unconventional interactions between the two.