Failed kamikaze pilot Ken Asuka becomes a rough, tough hooligan who settles all of his problems with karate, until he learns about the legendary swordsman Musashi Miyamoto in the novels of Eiji Yoshikawa. Resolving to live his life like Musashi, he begins to take karate more seriously. Based on a manga by Ikki Kajiwara and Jiro Tsunoda, itself inspired by the real life of Yasunobu Oyama, the founder of the "hard-knock" Kyokushin Karate school.

It is the time of civil war. Zipangu is a country where people live together with gimmick warriors, a kind of super human robot. There, people and gimmick warriors struggle to seize power. Musashi, a Samurai gimmick warrior, departs to on a quest to become the best Samurai warrior. Musashi thrives in the series of battles, encountering with many heroes and villains including his lifelong rival, Kojiro, an expert swordsman. Later, Mushashi and Kojiro are sent by their General to escort the Princess, a granddaughter of the general. The princess is spoiled and difficult, so their journey becomes series of misadventures. Soon, they are caught up in a battle to seize control of the Country.

A short rotoscope film by Mika Seike.

Special music videos released with the Kagi Hime Monogatari: Eikyuu Alice Rondo DVDs.