Tatsuya visits his aunt Ria's house during summer break. She is a kind and beautiful woman, someone Tatsuya has admired since childhood, and as he's grown into a man, his feelings for her have deepened. However, faced with the reality of her marriage, Tatsuya struggles to suppress his emotions. Sensing his inner turmoil, Ria suddenly proposes something that shakes him to the core: "Let's bathe together again, just like we used to?"