It'd be a bonus to do so if you already have them in mind but aren't needed. I didn't want to force someone to come up with their star upgrades immediately but the activity/club you will be a part of should dictate what it does to some extent or another. 

Edit: The reason I'm asking Tatsua for hers is because the ghost club seems a bit abnormal when it comes to ability and I'm unsure about what it could do.