Tsuyoshi was Chipp Zanuff's sensei and the man who changed his life. Tsuyoshi was a ninja master who saved Chipp when he was about to be killed by the mafia. It was his tutelage that changed Chipp from a biochemical drugs dealer to the man he is now. He was also the reason for Chipp's obsession with the Japanese culture. He was killed by the Assassin Syndicate before the events of Guilty Gear. The novel The Butterfly and Her Gale reveals he was killed because he was an undercover agent of the International Police Force who infiltrated the Syndicate until they found out about his true identity.
In Guilty Gear Strive, a special interaction can occur between Chipp and Nagoriyuki where the two imply that Nagoriyuki was also mentored by Tsuyoshi.
- In the BlazBlue series, Jubei was Ragna's teacher and the one who saved him from death. In addition, one of his aliases is "Mitsuyoshi".