Challenges are the various tasks you can do while living out each Life. Some Life Classes require you to perform the tasks while you are that particular Life, while others can be done while using any Life. For completing the task, you will earn stars, which contribute to leveling up that particular Life.
For any stars you have acquired, you will need to switch to that Life and then speak to your respective Master. Note that some challenges are not visible right away, as you will need to speak with a person related to that Life in order to unlock them (usually the master or one of the people you talk to when starting out). These people are usually designated with a question mark over their heads and will be listed under each respective Life Class.
