An early Miike. It's an interesting film if you're interested in the evolution Miike went through as a director. Shinjuku Triad Society bears the strengths of his later crime films, but the execution is still pretty inconsistent and unpolished. While there are flashes of genius present, the film itself is a little too uneven to be a true Miike classic.
The plot revolves around a badass cop whose brother, a lawyer for the Chinese Triads, is murdered by members of a local Yakuza gang. Rather than let the official investigation run its course, he sets out to find the culprits. He finds himself in the middle of a gang war, but won't let that get in the way of his revenge for his brother's assassination.
Miike relies on a solid cast, there are a few very memorable scenes and the pacing is solid enough, but there is simply too much mediocre filler here. It's clear that Miike was still trying to find his way when he made this film, but at least there are several scenes that will stay with you long after the credits have faded. Decent filler.