Nacchan (nickname) decides to join a university club that her high school senior, whom she has long admired, belongs to. Despite having a boyfriend, she naively follows the senior's invitation and joins the club, eventually participating in a welcome retreat trip. As she boards the vehicle full of excitement, she realizes all the men present are strangers—none of them her boyfriend. Eager to impress her admired senior, Nacchan proudly displays her submissive side, spreading her legs before him. However, she soon discovers that the senior is already involved with the other men at a private hot spring! Panicking, she attempts to leave, but the situation has already spiraled completely out of control.