We stayed as a couple in this hotel for 7 days and have mixed feelings, hopefully this review will help future travelers.
The best things about it: location wise is excellent. It's right next door to one of Ueno's station entrances. It has a supermarket right across the street and surrounded by coffee shops and restaurants. The hotel is amazingly clean and the AC and other amenities are brilliant. The most convenient feature is that they give u free wifi routers which are very reliable and it was a joy and very useful to have high speed Internet around the clock.
The negative: The rooms are tiny. As in barely fit for two people to be in the room at the same time. You have to be creative as to where you would be able to place two average luggage pieces. The front desk staff and everyone are extremely polite but they do not know ANY English. This makes it hard to ask directions or advice for anything, just don't bother. Not much seating space in lobby other than one couch so can't wait for anyone.
Overall, if you don't suppose you will mind the negative, go for it. We got used to everything by our second day and then we were really ready to enjoy Tokyo.