801shiki Junior High School Student's Diary

Tonari no 801-chan is narrated by Tibet (otherwise known as Tibe-kun/Chibe-kun?), a twenty-eight-year-old company employee and boyfriend to Yaoi, otherwise known as Yaoi-chan. Yaoi, who also works in a company, is a twenty-two-year-old fujoshi, a female otaku who is a fan of anime and manga series featuring yaoi, or romantic relationships between men. Tibet, who is an otaku himself, initially met Yaoi over the Internet. When she obsesses over yaoi, a small green furry monster comes out of a zipper from her back as the manifestation of her obsession.

Junior-high school student Rei Hoshino, a fujoshi who does not especially have any interest in the 3D aspect of life, suddenly changes when on a rainy day she takes interest in a high school student named Kei Akai and wants to get into the same high school as him. To that end, she enlists the help of her childhood friend Shōtarō Kamiyu who helps her study for the entrance examination, and diet so as to become a cuter girl. All goes according to plan, until a scheming girl going to the same school named Luna Kurotsuki makes it harder for Rei to get closer to Kei.