Ohitsuzen - choice of meat or fish (choose bbqEel) on a bowl of rice, with various condiments and miso soup. You mix it all together with brown ricetea. It's delicious and very cheap! 1850Y each.
I didn't love the raw tuna. But I LOVED the unagi (eel) Ohitsuzen. I had never had Ohitsuzen so the server helped show me how to do it. Fun experience, excellent unagi.