Kare no Shiranai Himitsu wo Irete.

Two months into their relationship, Yui and Naoya are still navigating the unfamiliar territory of being a couple. Their tentative romance takes a dark turn when a stranger approaches them on the street, casually calling out Yui’s name. The man standing before her is no ordinary passerby; he is the person to whom she lost her virginity. Driven by youthful curiosity about intimacy before she ever began dating Naoya, Yui had slept with him—a decision she believed was firmly buried in her past. Now, that hidden history threatens to unravel everything she has built. Rather than walking away quietly, the man leverages his knowledge of their encounter, threatening to expose Yui’s secret to her unsuspecting boyfriend. Caught between the fragile new relationship she cherishes and the shame of her previous choices, Yui finds herself trapped in a suffocating web of anxiety. As the pressure mounts, she realizes that the things she cannot bring herself to tell Naoya are only beginning to accumulate, forcing her to carry a growing burden of lies and silence that could shatter her happiness at any moment.