An OVA bundled with the limited edition of the tankobon of the Kyou no Go no Ni manga. The staff and the cast of the OVA are the same as those of the Kyou no Go no Ni TV anime.

In Japan, the country that inspired the slogan "Born to be Mild," the blood of young men still runs hot. In the old days they'd go off into the country and hack each other up with swords, but these days, what with school, that isn't very practical. So some of them do something very un-Japanese. They strap on a big bike, roar around annoying people, and pound anyone they consider dishonorable. Now meet Eguchi Yousuke, leader of a high-school Biker gang AND the school's handicrafts club. Which means he divides his time between fistfights and fancy needlework. And if you think he's weird, wait until you meet the rest of his gang...

The fate of mankind is doomed in the early 21st century due to losing "purana," an essence of living force supporting all life forms. Not willing to witness the extinction of mankind, a vampire named Duo disclosed the secret of purana to humans, saving the latter from destruction. However, just like Prometheus in Greek mythology got punished for bringing fire to mankind, Duo is punished for breaking the taboo. The vampire sent to punish him is Zieg, Duo's best friend, or, more than the best friend.

The genius robotics professor, Dr. Komyoji has created Jiro (who has the ability to transform into Kikaider) – a humanoid robot tasked with the protection of Dr. Komyoji’s son, Masaru, and daughter, Mitsuko. Gifted with a conscience circuit, which has the power to simulate real emotions that helps to distinguish between “right and wrong”, Jiro must protect Mitsuko and Masaru from the evil Dr. Gil who wants Jiro to join his army and aid in his goal of world domination. (Source: ANN)