Sixteen years after its destruction by a meteor, Graviton City has been rebuilt into a futuristic metropolis. However, this is of little concern to superpowered high school student Eiko Magami, who only cares about her best friend Shiiko Kotobuki and arriving at school on time. Unfortunately, the incredibly intelligent Biko Daitokuji intends to befriend Shiiko, taking Eiko's place as the Shiiko's best friend using any means she can. Biko decides that, to accomplish this, she must defeat Eiko in combat. In order to overcome her super strength and speed, Biko creates a mecha and challenges Eiko in front of their school gate. As the two commence their battle, an extremely large spaceship hovers over Earth, searching for something left behind.

Two years after the birth of the manga a pilot film was released. It was a brief film of only 13 minutes that had the purpose of assay the response to a possible future anime realization of Lupin III. The pilot opens with a challenge call from Lupin to Zenigata from a public phone.
(Source: AniDB)

A Kure-nai OVA featuring new character designs closer to the novel/manga.

A story about a goat and a wolf who become friends on a stormy night, and how they overcome differences and hardships.