Torajirō Shirakawa, a former yakuza boss and ex-rival of the protagonist Tatsu ("the Immortal Dragon"), earned the moniker "Steelfist Tiger" during his criminal career, recognized as Tatsu's only equal in raw power and ferocity. His physical appearance features fair hair and eyebrows, a long thin scar crossing the bridge of his nose and cheeks, and a heavily muscular, tank-like build in his prime, covered with extensive yakuza tattoos across his pectorals, shoulders, and forearms.

Imprisonment disconnected him from his gang. Upon release, discovering Tatsu had dismantled his clan, Torajirō abandoned crime, reinventing himself as a food truck entrepreneur. He initially specialized in crêpes, demonstrating exceptional dexterity and speed in preparation, later expanding his menu to include bubble tea, approaching culinary work with the intensity once applied to yakuza activities.

Initially harboring resentment toward Tatsu for destroying his gang, his grudge manifested as a competitive rivalry, shifting from physical confrontation to non-violent challenges like culinary "food wars." Despite this contentious history, Torajirō gradually developed respect for Tatsu's commitment to domestic life as a househusband, finding personal satisfaction in his civilian career and explicitly stating he no longer felt compelled to settle scores violently.

His character development reflects a pragmatic adaptation to post-yakuza existence, channeling former competitiveness into business endeavors by openly challenging other food vendors to prove superiority. Interactions with Tatsu evolved into a complex dynamic blending rivalry with mutual recognition of their shared transition away from crime, finding common ground through cooking and confectionery interests. His outfit potentially draws inspiration from Kazuma Kiryu of the *Yakuza* video game series.