This is another film based on the comics of Kazou Koike, author of other bloody, cynical comics made into movies, Lone Wolf and Lady Snowblood, for examples. This is probably some of the toughest material to my knowledge to get filmed.
The film opens with a couple, in feudal Japan, traveling with a map in the countryside. They are suddenly beset by sixteen children wearing demon masks. At first the couple seem defenseless but they pull out swords. The children kill them, lead by an adult man also in demon mask. OK, a little unusual but not special. Then during the fight one of the children is unmasked. The child runs and is killed by his leader! This is followed by a very rough training sequence that kills several of the children! Yikes, this is not a western film! Then the remaining children are gathered in a room and taught techniques of "sexual warfare" by their leader! First they witness two adult "demons", a man and a woman in masks, have sex then the only girl in the group is stripped and raped by the man. This is to teach her to use her femininity to achieve her demonic power. Then the leader instructs the remaining children to rape the girl as well! And they do. Japanese entertainment strikes again. At this point it becomes clear that the children are young adults now. The girl runs away and the leader instructs the boys to kill her. They capture her but refuse to kill her which pleases the leader greatly. They are all potential "perfect demons". He reveals that they are to protect the peace by killing anyone who attempts to overthrow the Shogun. OK! More mayhem ensues as the five are given instructions to blow up an armory.
The first 30 minutes of this film is hard to really describe properly. It's a torrent of sleaze and perversity that the remaining film has a hard time to live up to. What the leader does to himself is very unexpected. This is a blood gushing film and there's lots of it. The special effects are pretty bad and there is no attempt to cover it up. You can see the blood hoses or the padding where the bullet hole charge is put and one actor whose character's arm is cut off, is clearly bending his arm inside his shirt and squeezing a blood capsule. Fortunately the film, while not as well filmed as the Lone Wolf series, moves along at a good pace.
Sleazy, bloody entertainment.