Akio Nitta is the star slugger for Sumi Tech, the national Koshien tournament runner-up team. His serious commitment to baseball ignited after facing Kazuya Uesugi in middle school, an encounter that deeply shaped his athletic path. Previously, he had a delinquent background during junior high, where he befriended Harada. He lacks glasses, freckles, facial hair, and does not smoke. He has a younger sister named Yuka.

Years later, in "Touch: Miss Lonely Yesterday," Nitta continues his baseball career while Tatsuya Uesugi has quit the sport. Attending a different college than Minami Asakura and Tatsuya, Nitta develops a mild romantic interest in Minami and actively pursues her, contrasting with Tatsuya's emotional distance. This pursuit occurs while Minami feels neglected by Tatsuya, who is involved with another student, Kaori. Nitta offers Minami comfort and companionship, leading to a moment where she almost kisses him. She stops, realizing her enduring feelings for Tatsuya. Recognizing Minami's unwavering love for Tatsuya, Nitta steps aside. He confronts Tatsuya, urging him to acknowledge Minami's feelings and mend their relationship. This intervention contributes to Minami and Tatsuya reconciling. Nitta withdraws from the romantic conflict, allowing them to reunite before Tatsuya departs for professional baseball in the United States, demonstrating acceptance and respect for Minami's happiness over his own aspirations.