Nayu Hayama is a twelve year old girl entering Ounan Middle School, a private school for girls, at the top of her class. However, she trips on her way to give a speech at the entrance ceremony, exposing her lace adult panties. Nayu`s classmate Yako Jinguji witnesses the event and suspects her of paid dating, prompting Yako and her friend Haruka Shiraishi to go in search of the truth. Nayu gropes Haruka`s large breasts when the three meet in the hallway. With growing suspicions, Yako decides to get some photographic evidence.