Mikoto Shinozaki is a fifteen‑year‑old first‑year high school student who serves as the main protagonist of Over Drive. He is of average height and weight, with short brown hair and gray eyes, and often appears unkempt due to his untidy appearance and low self‑esteem. At the start of the story, Mikoto lives a quiet, uneventful life and is regularly bullied by older classmates. He lacks social awareness and confidence, making him an easy target. Deep down, he harbors a forgotten childhood trauma that makes bicycles instinctively frightening to him, and as a result he never learned how to ride one.

Mikoto’s life changes when Yuki Fukuzawa, a popular girl in his class and his secret crush, asks him to join the school’s cycling club. Although he initially refuses, his desire to impress her drives him to secretly practice riding at night. During this brief period he begins to genuinely enjoy cycling. Eventually he joins the club, vowing to become the greatest cyclist in the world and win the Tour de France. This ambitious goal reflects his newfound motivation: he wants to prove himself, earn Yuki’s respect, and escape his former life of passivity.

Within the cycling club, Mikoto encounters several key figures. The club’s leader, Yōsuke Fukuzawa (Yuki’s older brother and a skilled road racer), immediately sees potential in Mikoto and accepts him after a simple test. The vice‑president, Kōichi Terao, is initially reluctant due to Mikoto’s clumsiness and frail appearance, but changes his mind after watching him ride. Yuki remains a central emotional anchor, and her support helps Mikoto push through his doubts. Fellow club member Takeshi Yamato starts as a rival but later becomes a teammate who challenges and encourages him. Through these relationships, Mikoto learns not only about cycling but also about trust, friendship, and perseverance.

Mikoto’s most remarkable development occurs during his first competitive road race. Despite having almost no experience, he proves to be a surprisingly strong competitor. He finishes second in the sprint stage against the highly regarded cyclist Naoto. During the mountain stage, when Naoto attempts to break away, Mikoto—fueled by the crowd’s unexpected cheers—summons a second wind, charges up the mountain, and wins the King of the Mountain stage. His ability to shift into an unexpectedly large gear and maintain a high cadence astonishes everyone, including his own teammates. This performance demonstrates that his natural talent for climbing and his sheer determination can compensate for his lack of training.

Throughout the series, Mikoto evolves from a bullied, insecure boy into a focused, resilient athlete. He not only overcomes his fear of bicycles but also develops genuine bonds with his teammates and learns to believe in himself. His notable abilities include a powerful climbing style, exceptional endurance that allows him to recover from extreme fatigue, and an instinct for rising to the occasion when he feels the support of others. By the end of the story, he has taken his first major steps toward the dream of becoming a world‑class cyclist, embodying the idea that even the most unlikely person can transform through passion and hard work.