Celestine is a top 4* hotel (don't expect 5* facilities). I was positively impressed as I ended up there- sceptical - during the busy IMF week and our usual corporate hotels were full.
Good location, Nice lobby, friendly staff, nice well equipped room with decent size for Tokyo standards. The bed was comfy, the view through the big windows very nice. I had north east facing and could see the Tokyo tower.
There is free wifi across.
Highlight: there is special filter coffee package available something I haven't see elsewhere.
Only downside? There are not linked with any frequent flyer programm.
I did not try breakfast.