Players can store up to 5 Hearts.
Everytime you fail a level, you lose 1 Heart.

But that's not all.

You may request Hearts from Team Members and use them as you please.

By pressing the "Request Heart" button in the Team menu, a request is sent to your Team and members can send you a free Heart!
Sending a Heart to a team member is totally free. You can also gain some free Coins as well.

You may also earn Hearts as rewards in various contents.
Or purchase 5 Hearts for 100 Coins!