MISHAWAKA â Diner on 12th has sold and its last day under the current ownership is Friday. The restaurant at 1212 E. 12th Street is known for its American home style menu and fresh baked goods made by owner Kate Sergeant. The restaurant was initially listed for sale earlier this year with Sergeant saying the decision was due to her husband getting new job opportunities. Now, nearly four years after purchasing the business herself, Sergeant will say goodbye for a final time. âMy customers have become my friends and it's a very emotional time,â she said Wednesday. âIâm ...