Coins are a type of currency used in Pig&Dragon to purchase magic tools in the various mini shops. You can get coins by clearing stages. Coins will be given every time you earn new stars.
If you're cleared with the stage and play it again, not the same amount you received when you cleared it first time but less amount will be given. Also,You can collect coins by clearing levels and collecting them from your Pig&Dragon friends.
※If you closed the message box without taking the items (lives, coins, moves) from your friends when you start the game, some of the items will disappear. As a result, please close the message box after you receive items.