I'd heard hotel rooms in Japan were tiny, and was pleasently surprised by the size of the room. I had a twin room, shared with my supervisor and we weren't too much in each other's pockets. There was plenty of room for two large suitcases on the floor and for us to be able to walk around. The room was clean, fairly modern, though no wireless internet. The bed was quite firm, but I slept fine. The bathroom is very compact, but that seems to be standard.
Meals were a bit expensive, so didn't eat at the restaurant. We ignored the notices saying not to bring food or drink into our rooms, and they were polite enough not to throw us out! There is a mini-mart type shop on the ground floor which is very handy.
Staff spoke reasonable English.
It is a bit out of the way for the centre of Yokohama, but is almost on top of a subway station so is easy to get to. It is close to lots of restaurants.