Bought this from a Japanese website and was always a bit worried it was fake, thoughts?

Got this a year back or so for my Komiya collection, managed to get it during a bid. It was a good price but not a suspiciously good price, yet I can't shake the idea that it might be a fake card. The surface is not holo and looks good, as well as the corners. The colors seem fine as well and I don't see any glaring issue.

I'm mostly worried about the fact that it feels somewhat flimsy, but I chalked it up to being a Japanese card, and a promo at that, so the printing might have been different from standard.

Any thoughts or ideas to check for authenticity?