Also known as: 忍空, NINKU
NINKU -忍空- (にんくう, Ninkuu)
Originally a manga series that ran from 1993-1995. There was an anime series from 1995-1996, a film in 1996, and another manga series Ninku Second Stage: Stories of Etonins (忍空 -SECOND STAGE 干支忍編) from 1994-2011.