This is a movie that was created after the Sukeban Deka III TV series, and continues with the adventures of the Kazama Sisters.
Yui (Yui Asaka) is recruited as a student detective working for Seishonen Chian Kyoku (Youth Law Enforcement Division) headed by Kurando Sekine (Masaki Kyomoto). But she couldn't agree with the violent method used by the division, and resigns after letting go the students who were being persecuted by them. Kurayami Shirei (Hiroyuki Nagato) assigns Yoda (Nagare Hagiwara) to investigate Sekine. Yoda succeeds in obtaining a disk that contains the incriminating evidence but during his attempt to deliver the disk to the Kazama sisters, is fatally wounded and dies after he delivers the disk. Kurayami Shirei himself is jailed under a false charge of conspiracy against his country. Yui who was spending peaceful days in her native Kyushu decides to battle Sekine and his organization who is planning a coup against the government.
Although this movie was made after the Sukeban Deka series III TV, there's a discontinuity between the TV series and this movie. In the TV series, Kazama sisters comes from supposedly a clan of ninja, but there is no reference to this in this movie, and even the seed letter that appears on Yui's forehead never showed up in this movie. The story follows the pat Sukeban Deka formula that was developed in the first Sukeban Deka movie - that a zealot is planning to take control over the country, and Sukeban Deka battles to stop his attempt. I like the Sukeban Deka concept, and the Kazama sisters are still pretty endearing, but the story doesn't flow well in this one, and takes away from the excitement. There's not enough development of the story or the characters in the story that usually adds to the intrigue. But the most unforgivable sin is that even the beauty and the character of the Kazama sisters is not showcased in this movie. So the whole movie runs out of steam after a while.
This is the final chapter to the Sukeban Deka trilogy and is worth a watch if you are a follower of this saga.