It's never a good idea to shop for groceries when you are hungry, so it was very convenient that Misasa was in the small indoor shopping courtyard in front of Mitsuwa market; I was starving and I may have bought enough food to feed a family of six if I had not stopped to eat before entering the grocery store.
Misasa is one of the few places in the courtyard that serves grilled fish and"sets" (a meal tray with side dishes like soup, rice, salad). I chose one of the most expensive ones, the mackerel tray for $6.50, which included a big bowl of rice, half a mackerel, pickles, miso soup, cabbage salad, a scoop of potato salad, cold tofu with bonito, and a small hot tea, an amazing deal even for a semi-self service meal (you order and wait to take the tray to one of the tables yourself). The tray even included little containers of soy sauce and salad dressing already prepared for you (the counter has huge bottles of katsu, pepper flakes, and soy sauce if you want more).
They offer tempura sets with grilled fish or by themselves, or don bowls of rice with curry or pork katsu (fried boneless cutlet), and you can get grilled salmon or meat as your main course with all the sides. Just the variety of choices is a nice plus since the other eateries all tend to offer only ramen soup choices. Make sure you have cash on hand if you want to eat here; they do not accept any credit or debit cards. For the price of fast food at a big chain, you can eat a much healthier and tastier meal while enjoying fast Japanese soul food.
I think you are more imaginative and patient with your recipes when you've eaten before you begin cooking, so eating at Misasa may all inspire you to make something tasty when you get home.