When I'm staying in Karen I find the Tokyo Restaurant Karen a good option. Far better than driving all the way to town for a meal.
Its quiet a garden setting - if its warm enough to sit outside, when its cold you can sit near the log fire.
Service is friendly and am often greeted by the smiling owner. They do a very good (wow?) sauce on the salad which accompanies the Japanese dishes.
I bought a bottle of the sauce to take home and use. Best dishes I have had are Oyako Don. I normally stick to the Japanese dishes off the menu.