having suffered an injury during a soccer game, Ryoushirou Hayasaki returns to his parents' house to undergo therapy. As both of them are currently abroad, the only ones to welcome him home are his four older sisters—Yurine, Noemi, Naru, and Mio. His laid-back recovery is soon interrupted when they find their brother's erotic comics and love letters from younger classmates giggles Well, I don't think there's any explaining needed here. Boys having these things are just a given, right?