Great food, great atmosphere, good prices.
I moved to the neighborhood a couple of months ago, and Niwana has quickly become one of my favorite restaurants. Their menu is fairly large, featuring a variety of Japanese and Korean cuisine. There are plenty of vegetarian options, and the lunch specials (such as their bento boxes) are surprisingly inexpensive - around eight dollars.
The real test, of course, is the quality of the food, and Niwana doesn't disappoint. My usual is the vegetable teriyaki bento, which comes with three pieces of California roll, a small salad with ginger dressing, a rice ball, and fresh fruit. This is a great lunch.
I also like the dolsot bibim bap - a sizzling hot stone bowl full of white rice, topped with vegetables, and served with red chili paste.
You also get little dishes of kimchee, sliched radish, and other treats as appetizers. (I don't always know what I'm eating, but it always tastes good. Last time, I got some kind of translucent gelatinous blocks that may or may not have been derived from rice. Weird, but enjoyable.) Their edamame and these little tofu pancakes they have are also good.
The atmosphere is classy-casual, equally well-suited for a date, a small celebration with friends, or just an everyday lunch.