Hanbei is a fisherman living in a quiet seashore village whose life becomes intertwined with the fugitive ninja Kamui. His background is that of an ordinary villager, making a living from the sea and seeking a peaceful existence away from the violence that plagues the ninja world. His path crosses with Kamui when the rogue ninja aids him during a dispute over a crime involving a nobleman's horse. Displaying honor and compassion, Hanbei offers Kamui shelter and friendship, fully aware that doing so is a significant risk. This act reveals Hanbei's trusting nature and his genuine willingness to help others in need.

In terms of personality, Hanbei is defined by his sense of honor, his compassion, and his desire for a simple, honest life. He embodies the possibility of a normal existence outside the world of ninja clans and their violent codes. His motivation stems from a belief in second chances and the value of human connection over suspicion and self-preservation. He does not judge Kamui for his past but instead welcomes him into his home and community, hoping to offer the former ninja the tranquility he himself values. This acceptance, however, puts his family at risk, as his wife carries significant secrets, including her own concealed past as a rogue ninja who fears that Kamui's presence will draw pursuing clans and destroy the peaceful life they have built.

Hanbei's role in the story is that of a catalyst and a symbol of what Kamui is searching for: a life of peace, trust, and belonging. He represents the fragile peace that ordinary people can achieve but also the ease with which that peace can be shattered when entangled with the consequences of a violent past. His decision to befriend Kamui drives key plot developments centered on trust, the inescapable nature of one's past actions, and the clash between the desire for tranquility and the need to confront violence. The fragile peace of his household is maintained by his willingness to overlook the dangers posed by the fugitives he harbors, creating underlying tension within his home.

Key relationships define much of Hanbei's character. His bond with Kamui is one of mutual respect and friendship, as the fisherman offers the ninja the first real taste of a normal life. His relationship with his wife, whose name is Sugaru or Oshika, is built on a shared but unspoken past. She loves the peaceful life he provides, and he trusts her, unaware initially of the full extent of her secrets. His daughter, Sayaka, is another important part of his family, and she develops romantic feelings for Kamui, deepening the connections between the fugitive and the household. Hanbei's actions are ultimately driven by a desire to protect this family unit he holds so dear.

Regarding character development, Hanbei undergoes a tragic arc from a symbol of peaceful stability to a victim of the violent world he sought to avoid. His initial acceptance of Kamui is an act of faith, but as consequences from the royal horse incident and the arrival of ninja pursuers threaten his stability and family, his peaceful life is destroyed. His story illustrates the fragility of peace for ordinary people who become entangled with fugitives. The development of his character is tied directly to the erosion of his safety, culminating in the tragic loss of his life and the lives of his wife and daughter when a ninja pursuer, disguised as an ally, massacres the village to corner Kamui. Hanbei does not possess notable abilities in combat or ninja arts. His strengths are his honor, his compassion, and his capacity for trust, which stand in stark contrast to the shadowy skills of the ninja world. His significance lies not in what he can do with a weapon, but in what he represents: the normal, honest life that Kamui desperately wants but cannot have.