Jiro is one of the main characters in the anime Blue Dragon: Trials of the Seven Shadows, known as a skilled and determined warrior who serves as a key ally to the protagonist, Shu. His background is marked by tragedy; both of his parents and his younger sister, Jina, were killed when the Grand Kingdom attacked his home village of Muffei. This devastating event fueled a deep desire for revenge, leading him to travel with the warrior Zola, who helped him awaken his shadow, the powerful Minotaur. As one of the descendants of the Seven Light Warriors, this power is integral to his identity, though his journey forces him to reevaluate his reliance on it. In the first series, Jiro is often consumed by his quest for vengeance against the Grand Kingdom and its leader, Nene, which makes him cold, arrogant, and prone to impulsive fits of rage. He frequently clashes with the more straightforward Shu, acting as his rival and often looking down on him.

By the time of Trials of the Seven Shadows, which takes place after the final battle against Nene, Jiro has undergone a significant shift. Having lost the ability to summon Minotaur, he embarks on a solitary two-year training journey in the mountains, questioning what he can accomplish without his shadow. His primary motivation becomes a personal rivalry with Delphinium, a shadow user he has fought many times. He is determined to prove that he can defeat a shadow wielder using only his own strength and swordsmanship, refusing to rely on Minotaur even after reuniting with Shu. This quest for self-reliance defines his role in the story, as he initially declines to rejoin Shu's party, choosing instead to track Delphinium alone. He later cooperates with Xie, the sister of the informant Homeron, gathering intelligence and continuing his pursuit. His path crosses with Shu's group at several points, and he ultimately regains his shadow, Minotaur, from Hildegard, joining the others for the final battle against the primary antagonist, Rudolph.

Jiro's key relationships are central to his character development. His dynamic with Shu is one of rivalry and begrudging respect; while he is initially hostile and cold toward him, their shared battles forge a bond of friendship, though they remain competitive. He holds a deep trust in Kluke, who reminds him of his deceased sister, making him more open and protective of her. In contrast, he maintains a distant and often irritated relationship with the clumsy Bouquet, though he does feel a sense of duty to protect her in dire situations. His interactions with Delphinium are defined by their many battles and his intense drive to surpass her without using his shadow.

In terms of abilities, Jiro is a highly skilled combatant. His most notable power is his shadow, Minotaur, a formidable creature associated with immense physical strength. However, his most remarkable development in Trials of the Seven Shadows is his growth as a pure swordsman. His intensive training allows him to fight on par with Shu and his Blue Dragon without using any shadow powers, a testament to his physical prowess, technique, and strategic mind. Throughout the series, Jiro evolves from a revenge-driven and impulsive boy into a more reserved, self-sufficient, and introspective warrior. He learns to temper his emotions and finds an answer to his own question of what he can achieve through his own human strength, ultimately accepting his shadow as part of his identity once more.