Mitsuyoshi Anzai, the respected coach of Shohoku High School's basketball team, commands deep admiration across Japan as one of its top coaches, earning the title "Anzai-sensei" from peers. His present calm and collected presence marks a profound shift from his earlier reputation as the demanding "White-Haired Devil" during his college coaching tenure. This transformation stemmed from personal tragedy involving Ryuji Yazawa, a talented college player under his guidance. Frustrated by Anzai's rigorous focus on fundamentals, Yazawa disregarded Anzai's advice and left for the United States. Five years later, Anzai learned of Yazawa's death in a high-speed car collision, reportedly involving drugs. Receiving an unsent letter from Yazawa's mother, Anzai read Yazawa's profound regret over his decision and descriptions of his difficult American college basketball experience. Deeply affected, Anzai resigned from college coaching, adopting a gentler approach that earned him the nickname "White-Haired Buddha".

At Shohoku, Anzai demonstrates exceptional strategic insight, identifying players' potential and crafting tailored training. He recognized Hanamichi Sakuragi's athleticism and rebounding talent early, making him a starter despite his beginner status. To address Sakuragi's shooting weakness, Anzai assigned him a regimen of 20,000 jump shots in one week before the national tournament, later guiding him to develop a reliable shooting spot at the 45-degree angle on the right high post. Anzai's motivational skills shine in key moments, like bolstering team confidence before the Sannoh match and advising Kaede Rukawa to aim for Japan's top high school player rather than rushing to America.

Anzai maintains tolerant but principled discipline. He overlooks Sakuragi's habit of jiggling his chin or belly fat and addressing him disrespectfully as "Oyaji" or "Pops". However, he enforced consequences for serious misconduct, benching Sakuragi, Rukawa, Miyagi, and Mitsui during the first Interhigh game after their fight involvement. His players hold deep respect; Mitsui credits Anzai's advice—"Until the very end, never lose hope. It's when you give up that the match is over"—for his pivotal middle school victory and specifically chose Shohoku for Anzai's mentorship. This loyalty saw Mitsui place Anzai's photo on the bench and pray to it when Anzai missed the Ryonan match due to a heart attack.

Physically, Anzai is characterized by his white hair, portly build, distinctive Santa Claus-like laugh ("Ho ho ho"), and a background as a skilled shooter, notably outperforming Sakuragi in a contest. His surname combines "peace, quiet" (安) and "west" (西), while his given name means "light" (光) and "righteous" (義). Trivia notes inspirations from NBA figures: Phil Jackson ("Zen Master") for handling strong-willed players, Jerry Krause for physique, and Gregg Popovich for Sakuragi's "Pops" nickname. Localization led to alternate nicknames like "Fat Chicken" or the erroneous "Coach Cock" in early English dubs, later corrected to "White-Haired Buddha". A cultural crossover exists with Taro Sakamoto from *Sakamoto Days*, whose retired hitman character shares physical similarities acknowledged by the manga's creator as an homage.