[Asagi Ryuu] Onee-san ga Iyashite Ageru Ch.1-5 [biribiri]

A lonely married woman named Emiko offers a younger man the kind of healing only an older lover can provide, and their tender arrangement soon deepens into a secret affair carried out in steaming baths, quiet bedrooms, and stolen afternoons that end the moment her daughter Tomoka calls that she's home. Every encounter leaves more evidence behind—lingering kisses, condom wrappers accumulating beside the mattress—while a quiet countdown hangs over them both, only a few months left before they must decide how this all ends. Bittersweet and aching with guilt, it's the story of two people who know their affair cannot last yet keep choosing each other anyway.