One of my favorite restaurants in Cheonan, South Korea is a hot tofu soup restaurant called LA 북창동순두부. I think it’s a chain that you can find in other cities, so if you see it elsewhere, you should check it out. The restaurant has the traditional Korean soup in different variations such as dumplings, curry, etc. for up to 8,000₩.
You can find this restaurant in downtown Cheonan, in the Yawoori area. There is a map on the Foursquare page.