Box! (2010)

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.