Mutsuka is a great host who responded my request and inquiries quickly! The room is exactly what you can see from profile pictures, very neat and tidy:)
Only one thing that I have to mention is that at night time, a smell of sewage was noted at bathroom, but it’s gone by next morning.
Location is very good as well, close to Roppongi-1 chome station and the instructions that Mutsuka provided was very easy to follow!