Originally Posted by Palsa

I managed to get a secret unnamed 2 star character on the second mission: "I don't want to be Santa -Intermediate-", the one that takes 20 stamina.
Here are a couple of screenshots:



Keep in mind, that since she's a 2 star you will have to manually lock her afterwards, if you manage to find her.
So far I've gotten her twice, both when replaying the second mission, I did not get her through the first play-through, so she might be available through the other missions.

I'm like 99% sure she wasn't intended to be in the game yet and just a consequence of us skipping events. If you have her, I'd hold off on doing anything with her since she might cause some weird bugs.