Since it's a honeymoon trip do consult your partner, if it's a first trip we tend to want to cram the itinerary, remember to include their interests as well. It'll be your first official trip together as a married couple. Unless he/she wants it as a "surprise".
My take is to avoid business hotels in central Tokyo. 13sqm is too small for a honeymoon trip, and that semi-double bed is only 120cm wide. Either splurge a bit or focus on overnight trips outside Tokyo where the rooms are bigger. If you are feeling really adventurous go try out the love hotels. They have really big rooms (and beds) but generally don't take reservations (in English anyway)