OVA
Description
Kojirô stands as the central protagonist throughout the Fuma no Kojirou narrative. A member of the Fuma ninja clan, historically aligned with Japan's Hojo clan during the Sengoku period, the Fuma operate covertly in the modern era.

Hakuo Academy suffers decline as rival school Seishikan poaches its top students. Acting principal Himeko Hojo, granddaughter of Hakuo's former principal, enlists the Fuma clan's aid. Ranko Yagyu delivers the request, prompting the Fuma leader to dispatch Kojirô to Hakuo. There, he clashes with the Yasha clan—ancient Fuma rivals backing Seishikan—reigniting a ninja war dormant for five centuries. Kojirô's clan brethren gradually join the conflict.

During early battles with the Yasha, Kojirô learns his sword, Fuurin Kazan, is one of ten mythical Sacred Swords. Yasha leader Musashi Asuka wields another, Ougonken. Their emergence draws Chaos, a group collecting all ten swords to grant ultimate power to their leader, the Chaos Emperor. After the Fuma defeat the Yasha, Chaos annihilates the Fuma village, killing the clan leader.

This massacre propels Kojirô into the Sacred Sword War between Cosmo and Chaos forces. Pursuing vengeance and opposing Chaos, he reluctantly allies with former enemy Musashi Asuka. They unite with other Sacred Sword wielders: Fuma clansman Ryouma (Seiranken), Soushi Date (Gurenken), and Sigma (Byakurouken), an ancient warrior sealed for 4000 years. Kojirô battles Chaos warriors Nero (Raikouken), Oz (Jyujiken), Jackal (Shikouken), Shura (Genmu Hishouken), and the Chaos Emperor (Houou Tenbu) in the "Holy Land Where the Swords Were Created"—revealed as the Moon.

Throughout the war, Kojirô witnesses vast carnage and uncovers the conflict as part of Saṃsāra, a cyclical cosmic battle dictated by karma and reincarnation spanning millennia. This revelation and the senseless bloodshed shift his perspective. He denounces the endless violence and destroys all ten Sacred Swords at the war's end to prevent future conflicts, defying their ordained destiny.

Post-war, Kojirô and Ryouma vanish for three months. In their absence, the "New Fuma Clan" (Shinsei Fuma) faction rebels under Shimon, who wields potent mind-control aided by warriors Muma and Raizou. Loyal Fuma remnants—Kirikaze, Shouryuu, and Ryuho—resist until Kojirô and Ryouma return. Kojirô leads loyalists against the New Clan, confronting Shimon to avert the clan's destruction in a civil war that nearly eradicates many members.

Years later, Kojirô trains the next Fuma generation. His peace fractures when the group Karma, led by the "Four Sword Kings," targets the Yagyu clan. Ranko Yagyu, who initially sought the Fuma's help, faces peril. Kojirô reenters combat to defend them, confronting mercenary Soushi Date and resurrected former Fuma brethren revived by Karma and turned against him.