Renzaburo Taki (voiced by Yusaku Yara) is an ordinary office worker, and he has another role that is unknown to ordinary people-"Dark Guard" (闇ガード), who is constantly fighting to maintain peace between the human world and the demon world. After receiving the task assigned by his superiors, he worked with the stunning beauty Makie (voiced by Fujita Yoshiko) in the demon world to protect the magician Joseph Maiado (voiced by Ichiro Nagai) to ensure his safety before the truce between the two worlds to be signed in Tokyo. After a fierce battle at the airport, Maiado was finally received, but he was a willful and lecherous old man. But the two escorted Maiado to the hotel based on their duties. Little did they know that the radical elements of the demon world had already set up an ambush and launched an attack with the intention of undermining the signing of the peace treaty. In the crisis, can Taki and Makie successfully complete their mission? As the situation develops, Taki and Makie discover the surprising truth behind the whole incident... The original plan for this film was only a 35-minute OVA, but later it developed into an 87-minute animated film when the storyboard was made.