I wasn't really sure whether to put this in the nightlife or dining category because, as with many places in Tokyo, the idea is to indulge in both food and drink at the same time, and you keep eating all night long.
Just to let you know, if you want to find it, its on the third floor in one of the buildings with lots of Izakayas (Japanese bars), like Tori-den, etc., on a big main street if you walk straight out of the East JR exit, along the shopping street and onto the next big road. There's lots of other similar places to choose from there too. I would, however, recommend this one, because it's cheaper, the service is friendly, and there's a great variety in the food.
I recommend getting the nomi-hodai, which allows you as many drinks as you can muster in the space of two hours. It's worth the money if you have three or more. Other than that, my personal favourites are the eda-mame, which are little green beans you take out of the pod yourself and very popular as a side-order anywhere, the tofu salad, and the fried chicken recommended to us by a certain Korean waiter . . .
Some of the staff, including the owner, are foreign, and therefore speak English as well as good Japanese, so you will have no problems. Plenty of young people go there due to the budget, and it certainly has a studenty feel to it. A casual atmosphere that I greatly enjoyed many times.