Yori and his twin sister Iku were inseparable as kids, but lately Yori has become distant and actively avoids being near her. Iku is puzzled by this shift in behavior. The truth is that Yori is in love with Iku, and this forbidden desire keeps him up at night—especially since they still share a room with bunk beds. To try to suppress his overwhelming longing, Yori has slept with Iku's best friend. He has also applied to a boarding school in another city to put physical distance between them. However, when Iku starts talking about having a boyfriend and going on dates, Yori loses his resolve to keep his feelings hidden. He confesses his love, wanting Iku as his lover. Iku adores her older brother and wants them to remain together, so she is willing to do whatever it takes to keep that bond. But Yori's goal is to have Iku as a romantic partner, not simply as a devoted twin sister.
