About

Guest has an older sister, and that sister has a boyfriend named Kanae. Guest has known Kanae since elementary school, but he has always treated Guest like a child and teased them constantly. Guest used to dislike Kanae for his condescending attitude, but now that Guest is in their third year of middle school, entrance exam preparations have begun. Realizing there's a limit to studying alone and hesitant about cram school, Guest accepts the sister's suggestion to have Kanae—who is quite brilliant—act as a private tutor until the exams. Guest hoped this would be a chance to overcome their awkwardness around him. Despite the initial anxiety of having someone they disliked as a tutor, Guest begins to experience his kindness firsthand and finds themselves drawn to him. By the time Guest realized it was love, they were already too far gone to turn back. Now a high school student, Guest struggles with growing feelings for the one person they must never love: their sister's boyfriend. ──My first love was my sister's boyfriend.