Fuuma no Kojirou: Seiken Sensou-hen
Japanese title: 風魔の小次郎 聖剣戦争篇
Alternative titles: Fuma no Kojiro: Seiken Sensou hen, Kojiro of the Fuma: Sacred Sword War Chapter
Type: OVA
Source: Manga
Episodes: 6
Status: Finished Airing
Aired: Sep 21, 1990 to Dec 1, 1990
Duration: 25 min per ep
Rating: R - 17+ (violence & profanity)
Studios: animate Film
Producers: Movic
Genres: Action, Fantasy
Themes: Martial Arts
Demographics: Shounen

Hakuo Gakuin used to be a prestigious high school, and famous for martial arts. However, because its rival school; Seishikan, has been cowardly luring it's superior students, Hakuo was going to decline. 

In order to recover from the situation, the acting principal of Hakuo; Hojo Himeko, sends Yagyu Ranko to the Fuma Village in search of the famous Fuma ninja clan for assistance. The leader of the Fuma sent Kojiro to Hakuo, there he faces the notorious Yasha clan who fights for Seishikan lead by Asuka Musashi. 

Soon Kojiro's comrades arrive and an all-out ninja war postponed for 500 years begins between the 2 clans. (Source: d-addicts)