King Battler Jr., a first-year student at Otokojuku, nicknamed "J." The fists of this man who has defeated countless formidable opponents hold a hidden past!! Just before the Tenchou Olympics, what kind of deadly training did he undergo to hone his punches to the ultimate level...!? The Otokojuku spin-off, The Legend of the Strongest Fist, which was a huge hit on the manga app "Manga TOP," begins!!