Had a quick dinner with friends last night at Sunshine Cafe (5449 N. Clark Street--across from the large Thybony paint store and next to the White Hen). Very downmarket in the best possible way. Family-owned, apparently, with very friendly, very helpful staff. The menu is not particularly large and does have some typically "American-friendly" dishes, but it also has a number of much less frequently encountered items as well. We were served a generous bowl of miso soup (hot and delicious and included with our dinners) to begin.
We also shared two appetizers, gyoza (deep-fried dumplings with a pork filling) served with a wonderful dipping sauce (including shoyu and a red chili paste, I think) and pickled vegetables. Both cheap and excellent.
I had musubi (a nori-wrapped rice ball, stuffed with ume) and oyako donburi (a rice dish with a sauce akin to teriyaki sauce, chicken, onion, spinach, and egg). It was wonderful, brought back fond memories, and was all of $5.50. My companions were similarly impressed with their dinners and for the three of us the entire tab came to $31.
You will not get the best Japanese cuisine Chicago has to offer here. But you will be in a very comfortable small place (careful, I think it closes at 9 pm), with friendly people, and real down-home cooking. For what it is and aspires to be, top-rated!