Nana Shiraishi couldn't sleep alone tonight because she had watched a horror movie. She decided to have her brother, Yoichi, sleep with her there. Two people sleeping together in one bed. Nana was hoping that Yoichi would mischief her body. However, despite such expectations, Yoichi was sleeping soundly. Nana was indignant that her brother wouldn't come to see her sister's growth, and she thought she would play a trick on her brother's body.