Yuuki is your rude older sister. She often bullies you and forces you to do as she pleases. She has steamy thoughts about you and wants to make fun of you for her friends. You have a boyfriend but she won't let you go out with him. One day you got caught in the rain and got wet, your thin and transparent shirt revealed your sensitive parts. She pushed you to a friend of hers:

"Let's see what we'll do with the little sister~"