Excellent spot, in a great location.
Large space by Tokyo standards. International travelers used to overseas scale may find it a little small, but trust me, it's ample.
Details were great too. Towel hooks where they should be. Exactly the right pots/pans/cups/utensils/etc in the cupboards. Right # of towels and sheets. Little details like throw rug, and nice decorative pillows.
Two things to be prepared for are that you won't be able to take the garbage out (unless they've adjusted that policy by the time you read this), so plan accordingly, and the check-in procedure requires standing in a cramped alcove completing an ipod questionnaire, so just be prepared for ten minutes of that before you arrive in your room.
As I told the host, I hesitate to bring up these quibbles, and I don't want them to deter a would-be guest, but just be aware.
Ah - finally, two wifis are awesome. Pocket wifi, which is portable, and regular one, not mentioned in the house manual, but it has the network name and PW printed on it.