maybe, not sure. but the alloy quality is different with most japanese brands. they use 7075, instead of 6061 which is what the lesser brands use. also the japanese brands seem to have more development in how they are designed (for example kawahara, 5 star, square etc).

3 racing chassis are good, but again lack the below points.
1)development; as an example, the 3 racing chassis are noticably heavier
2) alloy quality; im not 100% sure with the chassis but i think it is 6061 like all other parts. i don't see why they would use a special alloy just for the chassis. 7075 is usually shinier. (not always though). some 7075 doesn't anodise well also, so thats why most brands use 6061 when they anodise.

i have a japanese brand 4mm chassis for my mtx4. and it weighs the same as a 3mm and it is stronger than a rock! i bent a skyline rear crossbrance into a Z shape (no joke) yet the chassis is in the same condition as when i first got it