Hokuto no Ken Zero: Kenshirou Den
Fist of the North Star: Legend of Kenshiro
真救世主伝説 北斗の拳 ZERO ケンシロウ伝
Last of the Shin Kyuuseishu Densetsu pentalogy. A prequel set between Kenshiro's defeat at the hands of Shin and the beginning of the manga.
(Source: Wikipedia)
