Kage, or shadow, refers to ninjas. Aka Kage, or red shadow, is the ninja around which the story is centered. This movie is an adaptation of a tv series aired from 1967/4/15 to 1968/3/27 (52 stories) which itself is based on an ancient manga. The series introduced Japan to the wonders of color TV. However, like the new X-Men of the 2000 movie, the new ninjas refuse to wear their old corny costumes and wrap themselves in black bodysuits. The movie is a big long music video. The monotone techno beats flatten the movie's possible climaxes with the rest of the blah. The action is a lot of obvious stunt work, except for the thief played by gymnast Alina Kabaeva. Too bad the former professional sumo wrestler playing one of the thugs, Mai-no-Umi, has no chance to display the acrobatic skills that let him make sumo wrestlers twice his size bite the dust. Half of the plot tries and succeeds once out of ten times to make you laugh, the other half tries to be serious and make you feel for its flat characters--but the two never blend peacefully. This movie wastes all of its potential except on making Aso Kumiko (Asuka) look really hot.
As Samy Naceri (TAXI2) would say it: NINJAA!!