Doc Nakano, born Kazuo Nakano, provides color commentary for professional wrestling matches across the series. His character stems from a caricature of a real-life Weekly Shonen Jump executive, cementing his role as a recurring comedic fixture. Early manga chapters depict him habitually skipping work to attend wrestling events, often attempting to interfere in matches only to be instantly knocked away. His obsessive fandom once drove him to sell his wife for major match tickets.

Physically, Nakano appears as a short middle-aged man, marked by his ill-fitting wig that frequently detaches during broadcasts or humorous scenes, evolving into a signature visual gag. He reinforces this trait by calling himself "Aderans" Nakano-san—a reference to an actual wig brand—in his speech. Eccentric and bothersome, he’s universally viewed as foolish yet consistently laughs hardest at protagonists' mishaps. Initial storylines emphasize his fondness for gyudon, specifically served saranami-style with meat separate from rice.

Anime adaptations expanded his presence, transforming him from occasional cameos into a permanent wrestling commentator featured in nearly every episode. This shift redefined his marital dynamic: rather than selling his wife, he expresses excessive devotion, repeatedly invoking her name during commentary or tense moments. As an announcer, he partners with Mac—Nakano dissects wrestlers' techniques and predicts moves, while Mac offers colorful metaphors. Despite his expertise in wrestling mechanics, his toupee mishaps endure as a running joke.

All media iterations preserve his array of nicknames and titles, including "Aderans," "Art Nature," "Flying the World," "Slow Kazu," "Great Edo Sports Nakano-san," and "Chōjin Wrestling Commentator." His legacy includes placing 31st in an in-universe popularity contest.