I find it interesting that you guys are picking his lower body action as a con. Why is that? Why having the point of gravity forward is bad?
I personally like how his lower body works. Like many coaches recommend, this guy leads with his butt and for such a small frame he generates very much momentum with his legs.
But off course if somebody could enlighten me on what actually is wrong with the lower body action of this pitcher it would be great, because I personally can't see anything. I think the legs should be used to generate as much power as possible and this guy seems to do that very well.
I also like how he keeps himself balanced though the whole delivery despite leading so much with his hips and butt.
But I do agree that his timing is off and the arm is very, very "elbowy". That's can't be good. And I'm not 100% sure, but I think he also transfers poorly the momentum he gains with that unordinaty lower body action. For such a young and skinny guy he seems to have quite good velocity on that ball but I think that with a better upper body action he could transfer better that energy created with the legs and lower body. It looks that he could throw harder that that.
And yeh, what's up with Japanese pitching from a shorter distance? I wouldn't be surprised this particular guy does because he looks young and could still play some junior/little leagues games where they naturally have the mound closer, but I'm also quite sure the adult regulations for the mound distance is the same wherever your are in the world. It's default also in Japan.