Daizō Ban, father of Chūta Ban and president of Ban Automobile Industry, commands his corporate empire and family with a volcanic temper and iron-fisted authority. His rivalry with Hanagata Motors spills beyond boardrooms into high school baseball, where he exploits his role as Seiun High’s PTA president to sabotage opponents linked to his business foes, notably Kōyō High and its star Mitsuru Hanagata. As a key school sponsor, he wields unchecked power—interviewing students, manipulating team decisions, and sparking chaos, such as overfeeding players before a critical game, leaving them incapacitated. After Seiun’s Koshien defeat, he impulsively disbands the team, later framing Hyūma Hoshi for a staged attack to protect his interests, then stubbornly denying Hyūma’s reinstatement despite evidence of his innocence.

Daizō’s obsession with outshining Hanagata Motors drives even personal concessions: initially blocking Chūta’s baseball ambitions, he relents only to counter Hanagata’s marketing ploys, later christening a “Chūta Strong 119” dump truck to capitalize on his son’s athletic fame. In *Shin Kyujin no Hoshi*, his rebranded Ban Heavy Industries sees Chūta elevated to managing director, though their bond frays under Daizō’s resentment of his son’s baseball commitments.

A paradoxical figure, Daizō oscillates between vindictive scheming—orchestrating Hyūma’s enrollment at Seiun, destabilizing team morale—and sporadic displays of support, like rallying players before tough matches. His legacy hinges on relentless corporate warfare and fractured paternal ties, where pride and rivalry consistently eclipse empathy or reconciliation.