ROM Hack What Are .tkst files and How Do I Open Them?

[HeyImAmethyst]

There are these .tkst files I found in my extracted rom of the 3ds Japanese game, Tongari Boushi To Mahou No Machi and I don't know how to open them. They don't have any particular headers when looking at a few of them in a hex editor. If anyone can help me open these files, I would very appreciate it.