Meiou Keikaku Zeorymer

Hades Project Zeorymer (冥王計画ゼオライマー Purojekuto Zeoraimā?) is a manga by Yoshiki Takaya, written under the pen name Chimi Morio, and published in the adult manga magazine Lemon People from October 1983 to November 1984. A three-part finale was serialized in Monthly Comic Ryū in 2007. A four episode OVA adaptation by AIC tones down the explicit sexual content and deviates somewhat from the storyline and setting.

(Source: Wikipedia)