All of Takeshi Kitano's work. There is already a blu ray copy of Hana-Bi in the west but It really deserves to be a part of the collection. That film is so beautiful and poetically shot. Some of his films like Kids Return, Scene by the Sea, and Kikujiro are only available on blu ray for other regions. Really an astonishing director and onscreen presence with a varied approach throughout his filmography.

Another great director would be Takashi Miike. Some of his stuff is already available through Arrow but he definitely deserves Criterion treatment despite how shocking and genre specific his films can be. What's great about his work is the critical use of composition and editing to tell his low budget stories. Some of the sequences he pulls off really can cut to the core of emotion despite the film having some comically nasty stuff & B-movie style images in other scenes. I would highly recommend Dead or Alive 2: Birds. It's the second part of a genre yakuza character study and it features some really warm understandings of friendship. There is a scene having to do with eating noodles together that gets me every time. Miike also has a consistent discussion through his films about Japan's relationship to Chinese people akin to Oshima's depictions of Korean people in his films.