Naoto Watari has had his share of struggles: his parents died two years ago, and now he and his sister live at his aunt’s house. There, his desire to protect his sister earned him notoriety as “the guy with the sister complex”—which never mattered to him, as his sister always came first. But when Satsuki, a childhood friend-turned-enemy(?), becomes his school mate, Naoto’s ordinary life is thrown into chaos … and Satsuki may just be the beginning.
Naoto Watari is a high-schooler who treasures his little sister Suzu above anything, and he would use her as an excuse to avoid getting into relationships with girls. Having realized he can’t just keep doing this forever, Naoto decides to try to get into a relationship with his classmate, Ishihara-san. One day, Naoto catches a cold, so he has to stay in bed. His childhood friend Satsuki sneaks into his room to pay him a visit, and it just so happens that Ishihara-san is also dropping by. With Satsuki hiding in his futon and Ishihara-san being in the room at the same time, things just couldn’t be any more awkward for poor Naoto!