Atsuya takes advantage of the summer vacation and goes to visit her aunt Mizuki's house for the first time in a while. I can't look directly at Mizuki's sexy body, which is different from what I remember when I was a child. Mizuki is amused by her innocent reaction, and Atsuya is teased a lot...that night, by chance, she peers into her aunt's love affair. The next morning, Atsuya turns red as he remembers last night, and Mizuki asks him, "You were watching yesterday, didn't you?"