Hidden Quest Question

It sounds like you're referring to a hidden quest. If you carefully look through the in-game menu, you should be able to find the hidden stage. Would you like to check it out yourself?

It seems like if you break trees with a cat, the stage automatically clears. That's probably it.

I think it opened automatically when I moved to a different district. Leveling up is the best.

If you keep a record, the quest will advance automatically.