High School Girls chronicles the raunchy high school lives of main character Eriko Takahashi and friends Yuma Suzuki, Ayano Sato, Akari Kouda, Kyoko Himeji, and Ikue Ogawa ("The Moron's Group") as they attend all girls "mediocre princess school", Yamasaki Girls Academy Fuji High School (referred to as "Saki Girls" for short). The manga emphasizes that for the most part the stories come from Oshima's own real life experiences.