I had a fantastic experience here as a solo traveler.
As a solo traveler in Japan, I wanted to be able to meet more people in my Airbnb, and that's exactly what this allowed me to do. Each room has multiple beds and most of the people in my room were down to hang out and talk after we got back from whatever we were up to that day. It's also only a short walk from the main Shinjuku Station, and from a very interesting part of Shinjuku. Min and Haru were also very hospitable, and even though checkout is at 11 am, they let me keep my bags in the common room until I had to leave for my flight at 6 pm. Overall, I'm very satisfied with this Airbnb.
In short: this is a very well-run Airbnb that allows you to meet people. I highly recommend it.