The little sister was raped by her brother-in-law

Riko, a student, a brother-in-law and a simple NEET man … The two suddenly find themselves living under the same roof when their parents remarry. Her bored brother Niriko, who has suddenly moved in with her, is overwhelmed. Riko was forced to have sex with a secret electric massager and masturbate in her room for 3 days while her parents were away on a couple's trip. However, there is an unexpected coincidence between the two… Riko and my brother's sexual compatibility is truly the best. My rebellious tsundere sister gets inked by her annoying brother-in-law!