Real-life version! Returning to his hometown to tell his girlfriend he's getting married, but then starting a crazy few days with his stepsister. Kashiwagi Konatsu, Shimokawa Tsumugi. NIMA-073

The wildly popular work by author Nyan no Esa x Fitch, with over 270,000 copies sold, is being adapted into a live-action film by Kashiwagi Konatsu! To inform his girlfriend of his marriage plans, Ryuya visits her home. There, he reunites with her younger sister, Akane, whom he used to take care of. Unlike her innocent self, Akane has grown into a fully-fledged woman. That night, Ryuya and his friends enjoy drinks together, but his girlfriend, Yuha, falls asleep early. Seeing this, Akane seduces Ryuya beside her sister. Ryuya's rationality wavers, and despite feeling guilty, he engages in sexual relations…