Bankaku is the father of the protagonist Banji Suke and the husband of Banchiyo Suke within the Oira Sukeban universe. His personal history is marked by an unconventional beginning, as he married Banchiyo when she was in the fifth grade and he was in his first year of junior high school. This significant age gap results in Banchiyo being only eleven years older than their son, a family dynamic that becomes a recurring source of tension and comedy.

In terms of personality, Bankaku is consistently portrayed as hot-headed and delinquent. This temperament is not limited to his home life but frequently spills over into his professional endeavors, leading him to lose jobs due to violent outbursts, such as physically assaulting executives or company directors. This pattern of behavior, combined with his son Banji’s own expulsions from school, forces the Suke family into a cycle of repeated relocations after being driven out of their neighborhoods.

A central aspect of Bankaku’s motivation and role in the story stems from his anxiety about the relationship between his wife and son. He grows deeply concerned over what he perceives as inappropriate sexual tension between Banji and Banchiyo. Specific incidents, such as Banchiyo appearing near Banji in revealing clothing, heighten his worry about potential intimacy between them, and he often finds himself reacting to these perceived threats.

His key relationships are defined by a mix of fear, combativeness, and reconciliation. Both Bankaku and his son share a profound fear of Banchiyo’s volatile temper, often fleeing from her physical retribution. Despite holding a fourth-degree black belt in judo, Bankaku is frequently overpowered by his wife during their physical confrontations. Their marital interactions are volatile yet cyclical, featuring violent fights that abruptly give way to reconciliations and public displays of affection, often right in front of their son.

Bankaku’s actions directly drive the plot forward. After yet another forced move, he secures new employment using a falsified resume. More consequentially, it is through an administrative error in the enrollment process that Bankaku inadvertently registers Banji as a female student at Amazon Academy. He dismisses his son’s discomfort with cross-dressing, setting the stage for the series’ central premise. In one notable incident, Bankaku returns home to find Banchiyo in a sexually suggestive state near Banji, which triggers another violent altercation where she physically assaults him.

Beyond the original story, the character of Bankaku has been reimagined in the New Cutey Honey spin-off as Akakabu Hayami. In this iteration, he retains his comedic role and hot-headed personality, now married to Daiko Hayami. This version of the character is involved in a failed bank heist and demonstrates an exaggerated level of resilience, enduring severe physical beatings without significant injury due to his body type.