Airin's apartment is wonderful. Considering it being in Tokyo it's considered quite big. We loved the fact that it was in a residential area. There is also an elementary school right across the street. My kids loved watching the students go to school. But don't worry, you won't hear a thing during recess. The area is really nice an quiet.
The apartment was very clean and everything was easy to use/find. If you had an issue and texted Airin, she would get back to you within a few minutes.
When we got to the place it was unlocked and Airin checked in on us about an hour later.
There is free portable WiFi which was also amazing. You can carry it around the city with you and have internet wherever you go, no rooming charges or data usage from your own plan. So wonderful ^_^
All in all it was a great experience and when we go back to visit Tokyo, we definitely will stay at Airin's place again.