Just had to make sure as a lot of people on itch aren't on the latest version and when they read comments for further events in the game they get confused why they haven't gotten them.
To start the Dragon hair quest you have to be after the first collection day(day 33) and go to meet Katelyn in the office door near the stairs, She mentions stuff about another farm and how they have mermaids and that they need a exotic attraction as well. This starts the quest I have it covered in my walkthrough. {You may need to have Rika's light house quest completed before this pops it might not be tied to the collection event been awhile since I played through the game.}
After finishing the dragon hair quest you get the hot spring forest unlocked automatically so you should have no problem there.
Also I doubt you have the Rika questline finished as you need to have the witch unlocked to finish her questline, which you don't get till you finish the dragon hair quest lol.
Finally I redownloaded the game and it seems the bug for the quest not being shown as completed has been fixed as it wasn't in the quest log anymore. So this shouldn't be a worry sorry for giving outdated info.