Yori and his twin sister Iku were once inseparable, but recently Yori has become distant and avoids her. Confused by his behavior, Iku doesn't realize Yori is secretly in love with her. This forbidden affection keeps Yori awake at night, especially since they share a room. Desperate to quell his feelings, he even pursued Iku’s best friend and applied to a boarding school far away. However, Iku mentioning a boyfriend reignited his resolve, and he confessed his love to her. Iku loves Yori as a brother and is determined to stay together. But Yori desires her as a lover, not just as a sister.