Kekko Kamen (けっこう仮面, Kekkō Kamen?, sometimes romanized as Kekkou Kamen, Kekko Masked, Mask of Kekkou or Mask the Kekkou, and translated as Splendid Mask) is originally a shōnen manga series from Japanese creator Go Nagai, which spawned an OVA series and several live-action films. The manga series is about the misadventures of a student named Mayumi Takahashi who attends a boarding school called Toenail of Satan's Spartan Institute of Higher Education that is run by sexual predators. The teachers are constantly looking for ways to torture or humiliate the students, and from this the teachers derive sexual satisfaction. Takahashi's only protection is from a mysterious figure known as Kekko Kamen.

Kekko Kamen is a female superhero whose costume consists solely of red boots, gloves, scarf and a mask with long bunny-like ears. Her fighting style is graceful, and her finishing move involves driving the opponent to the ground with a flying headscissors takedown which presses her groin into the victim's face. While regularly considered as a hentai series, it doesn't have many explicit sexual situations, neither in the manga, anime or live-action series, though there is abundant female nudity in all of them.

Kekko Kamen is a parody of Gekko Kamen. It was originally a joke that Nagai sent to his editor expecting him to reject it. His editor, however, loved the idea and that started Kekko Kamen. As well as the similarity in name, both Kekko Kamen's and Gekko Kamen's true identity is never revealed. Even the name of the main antagonist is a parody: in Gekko Kamen it's Claw of Satan (サタンの爪 - Satan no Tsume) while in Kekko Kamen it's Toenail of Satan (サタンの足の爪 - Satan no Ashi no Tsume)

Ten live-action films have been made of Kekko Kamen, along with one OVA series. A photobook has also been made, featuring a martial artist as Kekkō Kamen. A sequel photobook featuring Kekkō Kamen's daughter, Kurenai Kamen, has also been made.

Source: Wikipedia