A google image search shows at least a few nursery images of bright red new leaves. Here's one from Conifer Kingdom that shows slightly more developed leaves-- you can see that a few of them are still bright red, with some transitioning to green:

Vertrees says the distinctive markings of the tree are more readily seen when placed in shade. Can you put it in shade for the summer and see what it does? ...Though perhaps it will be difficult to see typical markings and variegation on such a young specimen. Good luck!

Here is a link that might be useful: toyama nishiki

I'd be skeptical......I see no sign of any variegation, it is not a very robust cultivar and therefore rather rare. New growth is often "kissed" with red or pink but I would not expect to see new growth that intense a color red.....even in spring.

It is sometimes difficult to be completely assured of the accuracy of tagging on a very young tree but this just does not look like any 'Toyama Nishiki' I've seen.

Thanks for all the replies. Gardengal, I was hoping to get a confirmation from you. I don't think it is Toyama nishiki too, I compare it with my tamukeyama and they both look alike. And when I bought the staff said the tag might get messed up. With your vote NO, I am going to return it. Thanks a lot.