I stumbled upon (after looking for at least 30 minutes) what they were. They are called Bikkuriman (Surprise-Man) stickers, and i guess they are an obsession in Japane that started in 1977 and continues today. I remember i only had a couple that i had gotten from a Japanese kid, and i used to stare at it for hours and wonder what it said on the back.
My parents surprised me with getting me a whole box from Xmas, and i remember i was lucky enough to pull a metallic one out of the pack. I hope that they are still at my parents house somewhere, and i can honestly see myself starting to collect them again they were so cool
This is what they came in
And this is what they look like