Clean place although small, which was commented on several other reviews. I found the title slightly misleading. The house is about 8 minutes walk to Iidabashi Station which then takes about 15 minutes train ride to Shinjuku Station itself. The unit is on the ground floor facing the main road so sometimes it might be noisy with cars and people walking to work.
The place itself is clean and is sufficient for 2 people but might be a tight squeeze for 3. A mattress was provided but it took up half the space of the floor. Toilet/bathroom is well sized with necessary amenities. Washing machine is a plus but when you unfurl the drying rack, there is literally no walking space with the mattress on the floor.
There was some initial communication issues - no linen was provided for the mattress or blanket upon arrival but after multiple texts over 2 days, I was told to look for linen in the linen closet outside the unit.
Otherwise, reasonable stay in Tokyo.