S1, E1: 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.