Daigoro Ogami is the young son of the ronin assassin Ogami Itto, and he accompanies his father throughout their wanderings on what is known as the assassin's road, or the demon path in hell. His life before the road began in tragedy, as he was born from the corpse of his murdered mother; his father cut him from her womb before embarking on their life of vengeance. From nearly the moment of his birth, Daigoro was given a choice between a ball, representing death with his mother, and a sword, representing the difficult path of a warrior. By choosing the sword, Daigoro signaled his acceptance of the life he would lead at his father's side.

Despite being approximately three years old, Daigoro possesses a complex and often unsettling personality for a child his age. While he often exhibits the curiosity and cheerfulness typical of a toddler, he frequently displays a disturbing maturity far beyond his years, a result of the massive trauma he has endured in his short life. This combination of childish innocence and unnerving stoicism makes him a deeply ambiguous figure, often described as creepy by others in the story. One of his most notable expressions is the shishogan, a powerful death glare that most adult swordsmen cannot achieve, which he uses to unsettle his father's enemies.

Daigoro's primary motivation is tied directly to his father's mission of revenge against the Yagyu clan, as the two are inexorably bound to walk the meifumado, the road to hell. He does not question this path but instead accepts it as his reality, showing a fierce loyalty to his father and a commitment to their shared code. This is illustrated in a story where, after being arrested as an accomplice to a pickpocket, Daigoro endures a public flogging in complete silence, choosing to keep his promise to a stranger rather than betray her trust. This act of stoic courage demonstrates that he has already internalized a powerful sense of honor and professionalism learned from his father.

Within the narrative, Daigoro is far from a passive observer; he is an active asset in Itto's assassinations. His small size and innocent appearance serve as a false innocence trick, prompting opponents to lower their guard, which often proves to be a fatal mistake. In the film Baby Cart to Hades, he acts as a decoy, helping his father defeat a skilled sharpshooter with revolvers. While his father is a stoic who rarely displays emotion, much of Itto's tenderness is revealed through his actions and the high expectations he has for his son, whom he regards as a partner rather than simply a dependent. Daigoro's key relationship is, of course, with his father. Their bond is the emotional center of the story, a constant theme of family loyalty against a world of chaos and violence. He also has fleeting but impactful interactions with strangers he meets on the road, from desperate women to honorable ronin, who are often moved by his courage and unique situation.

Throughout the series, Daigoro shows significant development, evolving from a speechless infant into a young boy who can understand complex situations and take calculated actions. He learns the principles of bushido not from lessons, but from observing his father navigate the world of death and honor. He becomes more resilient and self-reliant, capable of being left alone for periods and making decisions that reflect his father’s code of keeping one's word and facing death without flinching. He is developing into a Consummate Professional, just like his father.

Notable abilities aside from his famous death glare include an almost supernatural stoicism in the face of pain and death. He does not cry or show fear during violent encounters, even when placed in extreme danger or when being tortured. He is also surprisingly resourceful, capable of performing tasks such as retrieving items from the water or serving as a strategic decoy in a life-or-death duel, always demonstrating a calmness that impresses even hardened warriors. His presence serves as both a weakness and a strength, making his father more fearsome as a Papa Wolf while simultaneously being the key that unlocks the humanity within the stoic assassin.