Everyone's Kokoro about summer vacation. Kentaro comes to visit his aunt Satomi, whom he secretly admires. Kentaro feels blissful spending time with the kind and beautiful Aunt Satomi, but... Kentaro's body has completely grown into that of an adult, so he is no longer satisfied with just looking. He can no longer suppress the urge to touch Aunt Satomi, to embrace her, to do naughty things to her. Perhaps knowing his feelings, Satomi gently reaches out her hand and gently guides Kentaro. A secret that only the two of them can't tell anyone. It becomes an unforgettable summer memory.