Yuichi Yamashiro lives with his twin sisters, Mikoto and Haruna. A few years ago, a sudden accident took their parents, leaving the siblings on the brink of being separated. But their aunt, Izumo Nijou, stepped in, and the three of them continued living together in their parents’ home. Mikoto, gentle yet sometimes strict, takes care of Yuichi like a mother. Haruna, though a bit rough around the edges and stubborn, always looks out for him in her own way. Life without their parents hasn’t been easy, but Yuichi cherishes his days with the sisters he loves. Years pass, and now Yuichi is in his second year of high school. Summer vacation arrives once again. He expects the same boring, sweltering days as last year. But then, something unexpected happens. “Hey, Yuichi… um, would you… want to go out with me?” On the first day of summer break, his classmate Wakaba suddenly confesses her feelings and asks him to date her. Yuichi doesn’t dislike Wakaba. In fact, he likes her. But— He feels an inexplicable guilt toward his sisters, Mikoto and Haruna. Torn, Yuichi struggles with his emotions. After much deliberation, Yuichi decides to give dating Wakaba a try, as if forcing himself to move forward. The next day, he tells Wakaba his decision, though a lingering unease sits heavy in his chest. That unease—it’s his forbidden feelings for his sisters. But as if to make him forget those feelings, Wakaba takes bold action. “I confessed to Yuichi… and he said yes. So… we’re not exactly lovers yet, but we’re dating now!” Wakaba proudly declares their relationship in front of Mikoto and Haruna, sealing it with a kiss. Mikoto and Haruna are left stunned. Wakaba, unfazed, continues to kiss Yuichi boldly, right in front of them. Shock, confusion, loneliness, and sadness— Yuichi sees the complex emotions in his sisters’ eyes as he feels something deep within himself shift. The stagnant “time” in his life begins to move forward, and he knows it. As the summer unfolds, who will Yuichi choose as his partner? Wakaba? Mikoto? Haruna? Or someone else entirely? A love story with just a hint of bitterness and a whole lot of sweetness, told across five chapters. And now, it begins. [Translated from the official website]