Set in a high school boxing club in Osaka, Kabu is a likeable delinquent who cuts up during classes, but works masterfully in the boxing ring. Then one day on the subway, Kabu takes out three thugs who are harassing a young couple. When Kabu gets off the train, he realizes that the man being harassed is his childhood friend Yuki, who moved away several years back. To Kabu's delight he learns that Yuki has now moved back to town and is now attending the same high school as Kabu. A few days later, Kabu insists to the timid Yuki to join the boxing club. After much badgering upon Kabu's part, Yuki finally decides to take up the boxing gloves. Although Yuki is completely new to the sport, he does train with earnest determination. 元放送作家の百田尚樹による青春小説を、「デトロイト・メタル・シティ」の李闘士男監督が映画化。主演は市原隼人、高良健吾。高校のボクシング部に所属するカブ（市原）は、怠け者だが天才的なボクシングセンスを持っており、試合でも連戦連勝を収めていた。一方、カブの幼なじみで気弱な優等生のユウキ（高良）も、カブに憧れボクシングを始める。無敵を誇る天才ボクサーのカブと、地道に努力を重ねていくユウキは、やがて運命のライバルとなる。
