The positive
Hisao's wife makes amazing sandwiches and leaves it near the front door.
Hisao's place is relatively cheap for Tokyo.
The negatives
Hisao's Airbnb is quite far away from the nearby subway and JR stations ( 15-20 minutes away from Nippori, 12-15 to Uguisudani, 12-15 to Iriya station).
Huge language barrier. Hisao speaks little to no English. Although I understand google translate is not perfect, everytime I communicated with Hisao over text, it felt unprofessional.
Rather than having the flexibility to check in during the check in time, I had to accommodate my check in time based on his availability. Rather than check in within the time posted on the Airbnb 4:00-11:00pm), I had to rush from the airport because he told me that would not be there between 6-9pm.
The hair dryer in the room does not blow hot air, only cold air. For the shower, it is extremely difficult to adjust the water temperature so that it produces warm water (it's either hot or freezing cold).
All in all, you get what you pay for. It's comfortable for one person, tolerable for two people.