親友が気づかぬ内に彼女を寝取るボク

All the boys in a class admire Yumizawa Miyu for her kind and cheerful personality. However, her smile was often cloudy because of a secret hobby of taking cosplay selfies and uploading them to social media with her face and name hidden. She was worried about being exposed by a certain girl in her class, but the protagonist and his friend successfully helped her by reporting the girl for violating SNS regulations and taking unauthorized photos. During this incident, the protagonist followed an unspoken rule among the class boys to not pursue Miyu romantically and instead anonymously encouraged and advised her. However, his friend pretended to be the him and took credit for helping Miyu, even starting dating her while also asking the protagonist to support his lies. The protagonist feels intense anger towards his friend and develops twisted hatred towards Miyu, deciding to take her body and make it his own.