In Nagasaki, in the 1870s, a young man named Kei'ichiro has defeated all his opponents and become famous for his incredible strength. But he wants to be the strongest man in all of Japan, and his unification of Nagasaki is meaningless to him. Then one day he's suspected of a murder. And lurking in the shadows is a beautiful woman...

Because of his virginity curse, Kei'ichiro can't touch a woman. To work off stress and hopefully find a girlfriend, he goes into town with his buddy. At a tea house they encounter a young girl, but she's actually a transforming fox. Kei'ichiro and his friend Hyakusuke are caught up in trouble over this.

Houkouin, the mysterious woman she has appeared around Kei'ichiro several times, attacks him in a giant robot. She attacks him to learn the power of his own giant robot, Susanwo, but overwhelmes Kei'ichiro instead. A surprising person saves him...

Kei'ichiro goes hunting for girls in town, but ends up in a fight with a traveling samurai. The samurai, who he thought was a man, was actually a woman in men's clothes. Otomi saves this woman, Hyougo Asai, when she collapses from hunger, and puts her to work with Kei'ichiro at the bathhouse. But she has something she's after...

Kei'ichiro learns that a kiss from a virgin will break the curse open him and asks Kiriko and Chiharu for a kiss. But his disregard for their feelings ruins the mood. Meanwhile, Otomi tells Kiriko the secret behind Kei'ichiro's virginity curse.

Hitobashi Shigeyoshi is another person like Kei'ichiro who can control an Onigami. He defeated the Black Ships that came to Japan 17 years ago, and became the hero who protected the Tokugawa shogunate. But now the other high ranking members of the shogunate hate him, and he is mostly kept in captivity. He begins a plan to eliminate the rot in the organization.

Kei'ichiro learns that the curse is gone and goes out on the town with Hyakusuke. Kiriko finds out and tries to stop them, but her old friend, Sutemaru has come to get her. Kei'ichiro is jealous of Sutemaru. Just then a powerful foe, the Shinsengumi, arrives!

Sakamoto Ryouma and his two foreign friends steal the seal required to activate the Susanowo from Kei'ichiro. To win it back he's forced to play a game of strip rock paper scissors, with Kiriko stripping!?

With Ryouma gone, Kei'ichiro and Kiriko begin to get closer. But Kiriko is upset that unlike Chiharu and Hyougo she can't pilot Susanowo. Houkouin appears and reassures her, but Houkouin actually wants something else...