The Gokuhi-gumi are a band of space Yakuza. Led by “Genji of the North Star,” they seek to go to war with other yakuza factions and generally cause trouble throughout the galaxy.

Hayato Jin is the leader of NISAR; a private owned research and weapons development organization based in Japan. He, and Professor Tachibana, have been developing various weapons and building up their forces to deal with a threat that started fifteen years ago: the mad scientist Rando. When Rando’s forces begin their terrorist operations around the world, NISAR begins its search for exceptional soldiers to pilot their super weapon, the Getter Robo.

Jubei Yagyu is the head of the Yagyu Clan following the events of Demonic Resurrection and has mostly retired from the world. A group of warriors decide to ask him if he wants to take over a post at their dojo, but Jubei is more interested in watching the Noh of his friend and subordinate Chikuami. 

The story takes place after the failed Shimabara Rebellion, led by Shiro Amakusa as a Christian uprising against the Shogunate. It ended…brutally, and Amakusa himself was executed. However, dark forces are at work, and Amakusa returns from the grave…