Youth of the Beast borrows heavily from Yojimbo and Fistful of Dollars. Jo rolls into Tokyo and auditions for the yakuza. He does this by demonstrating his willingness and ability to beat the ever-lovin' snot out of their minor members. It works better than you might think.
Wasabi is a very French movie. Or, perhaps, it is a very Luc Besson movie. The action is over-the-top. The plot, such as it is, is ridiculous. The actors aren't bad, but the acting sure is. The humor is sophomoric. And yet, it all kinda works. Well, it works if you enjoy movies like The Fifth Element (also from Besson).
You could probably argue that there is a deeper meaning and hidden signficance in this tale. A case could be made that it's not just a well-shot, slightly melodramatic, Japanese pseudo-noir. You'd be wrong, but you could argue it.
Mitchum has been hiding out in a small town running a gas station and pitching woo at an innocent local girl played by Virginia Huston. The movie opens on this as his past catches up to him. Douglas sends his henchman Joe to summon Mitchum. He goes to see Douglas with Huston and tells her his sad tale along the way which we see as the flashback. In sum, it's the tale of how he got tangled up with Greer and Douglas and how that ended with him living in a small town under an assumed name.