After moving into an apartment, I met a beautiful older woman living on the floor above. She always seemed kind and approachable, gradually drawing my heart toward her. However, I couldn't ignore the lewd sounds and moans coming from her room every day. I wanted to get closer to her, but her body held an unexpected secret. Once I discover that secret, my feelings will be deeply shaken. What does this older sister truly feel for me? And how will our relationship change after I uncover the truth?