The space is incredibly small. I barely had room to open my suitcase. But it's filled with a washer and other useful things so the space is fully used.
My only complaints are minor. There is a mirror in the shower and a small mirror you can set up, but it's hard to shave with either of those. Also there are no signs to know for sure you are in the right place. And it didn't really bother me but there are a few stains on the carpet.
But otherwise the bed is comfy, the toilet is bidet style, and there are plenty of amenities.
Also you are incredibly close to everything in Ginza.