Alone with her beautiful sister… Sudden tongue kissing, licking and fucking all the time… Am I the worst? Tsukasa Aoi.

One night, Aoi suddenly appears at her sister’s house unannounced and drunk. There, she meets with her sister’s boyfriend, Yudzuru. And she immediately develops a crush on him, as she finds him particularly kind and cute. Aoi stays to sleep and sober up, and as it happens, her sister is going away to Tokio that very same day for job hunting. Which leaves Yuki and Aoi together for some alone time.