When Daigo was a young boy, he was saved from drowning on a river by Nishiki Matsugorou, Ikumatsu's father. In the process, Matsugorou lost his memories and married another woman, leaving his wife and daughter behind. This caused him to feel terribly guilty and responsible for Matsugorou's fate and later for his life as a homeless vagabond.
Daigo and his wife intended to turn their ramen shop into one that would be the best in Edo, but due to his sudden death by Jouishishi terrorists, they were unable to succeed.
Little is known about Daigo's appearance, with the exception that he had short-brown hair.
Daigo's brother would later come to the ramen shop, harassing Ikumatsu and asking a profit from the shop since it belonged to his late brother. The goons say that the money goes to their "rebellion" and if they can't get it legit, then they will have to steal it. Ikumatsu snaps upon hearing that and slaps the man saying that Daigo would still be alive if it wasn't for scums like them.
After denying him the money, he would kidnap Ikumatsu and try to sell her off to a brothel. However, Katsura, who had worked as a waiter in her shop to hide from the Shinsengumi, eventually came to her rescue. They were able to thank each other before Katsura departed, still on the run from the police force.
As shown in a flashblack, Daigo founds Matsugorou living as a vagabond and takes him to his ramen shop in an attempt to repay the debt of saving his life. He also wanted Matsugorou to see that his daughter was doing fine.
- The name of his ramen shop is an obvious nod to the martial art practiced by Kenshiro, the protagonist of Hokuto no Ken.