"Jigoro!" is a manga series that centers on the life of Jigoro Senba, a former yakuza boss who, after serving a lengthy prison sentence, decides to turn over a new leaf and live a quiet, law-abiding life. The story begins with Jigoro's release from prison, where he resolves to distance himself from his criminal past. However, his plans for a peaceful existence are quickly complicated by the lingering influence of his former life and the expectations of those around him.

Jigoro's attempts to reintegrate into society are met with numerous challenges. His reputation as a fearsome yakuza leader precedes him, making it difficult to find legitimate work or build normal relationships. Despite his efforts to remain low-key, Jigoro frequently finds himself drawn back into situations that require his unique set of skills, often involving protecting the weak or standing up to injustice. His moral code, shaped by his yakuza background, compels him to act, even when it risks exposing his past.

The narrative explores themes of redemption, identity, and the struggle to break free from one's history. Jigoro's interactions with various characters, including former associates, law enforcement, and ordinary citizens, highlight the complexities of his situation. While some view him as a threat or a relic of a bygone era, others see him as a protector and a man of honor. The series balances moments of intense action with quieter, introspective scenes that delve into Jigoro's internal conflicts and his desire for a second chance.

Supporting characters play significant roles in shaping Jigoro's journey. These include individuals from his past who either seek to exploit his skills or hold grudges against him, as well as new acquaintances who challenge his worldview and offer glimpses of a different life. The dynamic between Jigoro and these characters adds depth to the story, illustrating the tension between his old and new identities.

The plot unfolds through a series of episodic arcs, each presenting Jigoro with new dilemmas that test his resolve to stay on the straight and narrow. Whether confronting corrupt officials, aiding vulnerable communities, or facing off against rival gangs, Jigoro's actions often blur the line between right and wrong, reflecting the moral ambiguity of his circumstances. The series maintains a steady pace, blending action, drama, and moments of humor to create a compelling narrative.

Overall, "Jigoro!" is a character-driven story that examines the challenges of reinvention and the enduring impact of one's past. Through its exploration of Jigoro's struggles and triumphs, the series offers a nuanced portrayal of a man striving to redefine himself in a world that refuses to let him forget who he once was.