Kyotaro Oshima is a central supporting figure within the Kuroda Family yakuza organization. As the second-in-command of the clan, he holds the position of young chief and is frequently entrusted with leadership duties when the head of the family, Kuroda Ryuichiro, is absent. He is commonly referred to by the respectful nickname Kyo-san. Kyotaro is a man in his forties with a striking and memorable appearance, characterized by his slicked-back, Elvis-style red hair and brown eyes. His skin has a medium dark tan, and a prominent scar runs diagonally over his left eye, hinting at a history of violent encounters. His typical attire consists of a crisp white suit worn over a dark-colored button-up shirt.

In terms of personality, Kyotaro embodies a duality that is common among the Kuroda Family members. He is a devoted and honorable yakuza who operates with a strong sense of duty and loyalty. While his profession involves intimidation and force, his demeanor towards those he cares about is notably tender and paternal. He is gruff on the surface but possesses a deep well of warmth and earnestness, especially in his interactions with the protagonist, Yamaguchi Kumiko. His motivations are largely rooted in his loyalty to the Kuroda Family and his sense of responsibility for the people within his charge. He takes his role as a protector seriously, driven by a personal code of honor that places family, whether by blood or bond, above all else.

Kyotaro’s role in the story is established long before he physically appears. He was given the crucial task by Ryuichiro to be Kumiko’s caretaker when she first began living at the Kuroda household. In this capacity, he became the closest thing to a father figure that Kumiko has ever had, raising her and ensuring her safety. After serving a three-year prison sentence, his release marks a significant event, and he is welcomed back warmly by Kumiko and the rest of the clan. From that point onward, he serves as a steadfast guardian and advisor, often lending his combat expertise and wisdom to support Kumiko and her associates.

Kyotaro’s key relationships define his character. His bond with Yamaguchi Kumiko is the most significant. Although they are not blood-related, he considers her his younger sister. He took care of her with great tenderness and was personally responsible for teaching her how to fight, instilling in her the self-defense skills she relies on. This relationship is built on mutual respect and deep, familial affection. He also holds great respect for Sawada Shin, a close associate of Kumiko. Kyotaro is the one who bestowed upon Shin the title The Young Red Lion Master, acknowledging his strength and spirit. In a gesture that mixes his unique philosophy with mentorship, he even taught Shin about the nature of the traditional fundoshi undergarment, suggesting that wearing it could increase one’s manliness.

While the series shows the final results of her training, the narrative indicates Kyotaro’s significant off-screen development as a mentor, having successfully raised and trained Kumiko from a young age. Upon his return from prison, his development continues as he adapts to the current dynamics of the Kuroda Family and Kumiko’s new life as a teacher. He consistently demonstrates his unwavering loyalty and protective instincts, proving that his years away have not dulled his resolve or his skills. His notable abilities lie in his formidable combat prowess; he is an exceptionally skilled fighter, as evidenced by the fact that he was the one who taught Kumiko, who is herself a powerful combatant. His reputation and physical strength, marked by his scar, command respect within the yakuza world, and his tactical sense makes him a reliable second-in-command for the entire Kuroda Family.