OVA
Description
Masaru Aoki is a core member of the Kamogawa Boxing Gym and competes as a professional lightweight. His journey into boxing began not out of a childhood dream, but from a grudge. During his delinquent high school days, he and his best friend, Tatsuya Kimura, were local bullies who frequently picked fights. Their violent streak came to an abrupt end when they attacked Mamoru Takamura in an arcade and were soundly defeated. Seeking revenge, Aoki and Kimura followed Takamura to the Kamogawa Gym, intending to learn boxing solely to beat him. However, after winning their own debut matches, their goal shifted from revenge to admiration, with Takamura becoming their inspiration rather than their target.

Outside the ring, Aoki has a complex personal life that contrasts sharply with his fighting persona. He is the eldest of nine siblings and comes from a family that once starred in a television program about their large household. When his father fell ill, Aoki took over the family ramen shop, called Chuka Soba, where his natural cooking talent allowed the business to expand to three locations. He uses his earnings to support his siblings' education without hesitation. His love life is also a notable part of his character. After being repeatedly rejected by conventionally attractive girls in high school, he developed a romantic preference for women with less traditionally beautiful faces, a running trait in the series. He is in a relationship with a woman named Tomiko, with whom he shares an apartment.

Personality-wise, Aoki serves as the primary comic relief of the gym. He is playful, mischievous, and often the victim of Takamura’s pranks and harsh teasing. His behavior is frequently immature, and he relies on humor and buffoonery as a social mechanism, especially when facing anxiety or pressure. Despite his goofy exterior, he harbors the same deep aspirations as any other boxer. He has a strong sense of loyalty, particularly toward Kimura, his closest friend and partner, who is often grouped with him as the "Aokimura" duo. He is also a dedicated senior to the gym's younger members, like Ippo Makunouchi, often acting as a sparring partner and offering support from the sidelines.

Aoki's role in the story is primarily that of a supporting character and a source of levity, but he has significant moments of his own. His most prominent storyline involves his challenge for the Japanese Lightweight championship against champion Imae Katsutaka. Unlike the natural prodigies in his gym, Aoki is portrayed as a hardworking but less talented boxer who must rely on creativity to succeed. This match serves as an examination of two different paths to the same goal, contrasting Aoki’s choice to embrace life’s pleasures and his relationship with Tomiko against Imae’s decision to abandon all distractions for his career. The fight ends in a draw, a testament to Aoki's grit. His development is most clearly seen in his deep loyalty to Kimura. When Kimura prepares for his own title match against Ryo Mashiba, Aoki goes to great lengths to help, even begging Miyata Ichiro to assist in Kimura's training. During the match, when Kimura is on the verge of a brutal knockout, Aoki stops the coach from throwing in the towel, pleading to let his friend end the fight on his own terms so he would have no regrets, demonstrating the serious depth beneath his comedic surface.

In terms of boxing ability, Aoki is an in-fighter who lacks a natural finishing punch or special talent, often leading his matches to become messy, gritty brawls. To compensate, he is highly intelligent and creative, developing several unorthodox techniques to confuse and deceive opponents. His most famous move is the Frog Punch, which he conceived after a knockout loss when a frog landed on his hand, leading him to imagine leaping upward from a crouch to strike an opponent's jaw. He also utilizes the Look Away, a strange feint where he stares at a point in the distance, causing his opponent to instinctively look as well and create an opening. He has also attempted ineffective techniques like an untorqued corkscrew punch. While often downplayed as the weakest of the main cast, it is noted that his unorthodox style and resilience make him a frustrating and unpredictable opponent who has managed to rank highly in the national lightweight division.