A harcos szókimondó, szeretettel teli humorral átszőtt, és egyben megrázó története megtörtént eseményeken alapul. A film főhőse a hihetetlen visszatérést produkáló, és váratlanul bokszhőssé váló "Irish" Micky Ward, és féltestvére, Dicky Eklund. Akiknek előbb ellenfelekké kellett válniuk ahhoz, hogy végül igazi testvérekként tudják megszerezni a győzelmet, és meg tudják erősíteni a családi kötelékeket.
When the heroes of Fukuoka return after shooting "HEROHOUSE" in Nokonoshima, the find out that Fukuoka has been occupied by an evil secret society that has acquired a mysterious power. Ohgaman, the only one that didn't participate in the "HEROHOUSE" shooting, was injured by a young man named Tanaka Jiro and gives Jiro the mission of restoring peace in Fukuoka.
After 30 years of peace is Kisawazu, the Eight Swords of Sealing are scattered from the Yatsurugi Shrine once more. This even reawakens the Undersea Empire Zabun, who plan on finding the swords and using them to reawaken their master King Orga. As well as them, the mystical embodiment of the phoenix, Yatsurugi, arrives and merges with Takeru Yamato, a young fisherman and regular visitor to the shrine. Now with this new power, Yatsurugi, and eventually the similar deity Kisara, come forth to stop the unsealing of King Orga and return the Swords to the Shrine, as had been dne for many generations before them.
