Harenchi Gakuen (ハレンチ学園, Shameless School?) is a Japanese media franchise created by Go Nagai. Harenchi Gakuen was one of the manga serialized in the very first issue of Shueisha's manga magazine Shōnen Jump. The series was the first big success for Go Nagai. It is also considered as the first modern erotic manga, sometimes considered the first Hentai manga, though Nagai never used explicit sexual situations in the original run of the manga.
There are many works around Harenchi Gakuen, including numerous manga series, one live-action tv series, five live-action movies and one anime OVA. The first manga series was not adapted into an anime, but rather a live-action TV series; only the opening sequence to this television series was animated. This isn't the only show of Go Nagai where live-action and anime are combined: Pro-Wres no Hoshi Aztecaser features completely animated action sequences when the hero uses his powers, even though the show itself is tokusatsu.
Many comedies of Go Nagai use a similar setting as Harenchi Gakuen, while changing the situation. An example of this is his series Supeope Chu Gaku, a space school modeled in a similar fashion as Star Wars.