My classmate's friend is cool, good at studying and sports, very popular, and has a girlfriend, which is frustrating. According to what I hear, she likes to be spoiled and is said to be super sensitive. But one day, I saw him getting cozy with my sister! Could his girlfriend be my sister!? Ever since then, I can't stop thinking about my sister's body... Before I knew it, I was charging into the bathroom where my sister was.