Hi picked this card up very cheap from Japan on eBay. Not seen one in person before concerned it could be fake as the colour to me seems very dull and the quality doesn’t seem too good. Received some extras as well and on the back of these I noticed the bottom of the pokeball has a grey tinge. Every single one of my Japanese cards has a yellow tinge on the bottom. The cards are Surfing and Flying pikachu.
Edit* can’t seem to upload photos on my phone will do later.
Attached photos when you can
Without pictures I’m afraid we can’t really help… And not sure what you mean with the grey vs yellow tinge on the back side. Are you referring to the white or yellow parts of the old Japanese backs being grey instead of white or yellow?
Also, the English Grey stamp Ivy Pikachu, Japanese Flying Pikachu and Japanese Surfing Pikachu should all three be glossy cards. If they aren’t glossy, they are definitely fake. I actually have a fake (non-glossy) Japanese Flying Pikachu myself, so it might be similar as yours. Here is a real Glossy Flying Pikachu on the left, and the fake one I have on the right: