On four island (I think it was four, not sure), there is a boy in a house who gives you stickers for your trainer card. You have to clear events to get them, like beating the pokemon league, hatching eggs and winning from a friend battle. You can get several colours of them, depending on how much you did these. (You can always come back for a new colour.)
Yes it is fous island, the stickers go on the back of the Trainer Card.
Does anyone know how much you have to do things to get different colous? I've got the first three + the second egg sticker.
well i know u get another sticker at 40 times when u beat the elite four and the first time u hatch an egg u get a sticker and the first time u win a battle over llink cable u get a sticker and then the numbers of the aforementiontend things u can get more stickers