It was a fantastic stay! The room was very clean and homey. Koenji is a very cool and peaceful neighborhood to hang out and Choco's place is literally five minutes walk from the energetic bar areas around Koenji Station. Choco is very responsive on airbnb and his friend Aiko even treated me to a very local
izakaya (that I wouldn't have ever known without her) and brought me cakes and snacks as gifts to take with me! I would said it's one of the most wonderful stays I've had at airbnb.
There's only one small downside - since I had gigantic luggage it took a bit of effort to carry it to second floor from a narrow stairway. Other than this the experience was smashing.