Satoru's understanding and support, especially for a first-time newcomer to Tokyo was outstanding.
His super-simple check-in and check-out process makes it a relief, especially after you're going through the daunting process of learning the Japanese public transportation system for the first time––and that's just to get there (unless you were to drive or get a taxi there).
However, for those of you who haven't experienced small-space living in a big city like Tokyo, you may find it extremely cozy. The space is just comfortable and perfect enough for a single person, but maybe slightly less so for another. To make up for it, though, the apartment has all the charm of old-school Japanese home living, and all the amenities you would need for living relatively cheaply, if you needed to refrigerate and cook food (the built-in, outside-venting hood is nicer than most U.S. apartments), and the all-in-one bathroom.
Lastly, to reiterate Satoru's extraordinary hospitality, given permitting and reasonable circumstances, Satoru is a very reasonably accommodating host, especially since I experienced some scheduling inconveniences my first time.
If going by myself to Tokyo, I'd be happy to stay in Satoru's charming little apartment in Shinjuku again.