It's pretty interesting that Miike's reputation as a sequel hater lived on for quite a while, while some of his earliest films were in fact standard sequels. Bodyguard Kiba 2 is a basic follow up to the first film, but it's also the first part of a duology. Making sense of these old Miike straight-to-DVD projects can be a little tricky, luckily more info is available about these franchises compared to two decades ago.
Kiba is a sensei of a karate dojo who finds himself in some financial trouble. To keep his dojo open, he starts working as a bodyguard on the side. When he receives an assignment from a beautiful woman in Hong Kong, Kiba happily accepts. He is so smitten by her that his focus shifts, so when he is confronted by her assailant he finds himself at a loss.
The biggest strength of this film is the short runtime. It's not a superb film, but because most of the cruft has been cut there's not much time to get bored. The action scenes are a little dim and the signature Miike craze is still pretty tame, but the pacing is on point, the music is quirky and the little trip to Hong Kong makes for a nice variation on the usual Japanese setting. Solid filler.