Masa and his place is great. It is located in a quite neighborhood just 5 Mins away from train station, there are a bunch of convenience stores and a large supermarket between the station and Masa's place. It is easily accessible to and from HND by the airport bus at the next station. Unfortunately I didn't have time to visit the free onsen during my short visit, but it looks like it will be a wondering experience. Place can easily fit 2 people, and has all the basic appliances needed (pocket wifi provided as well). Will definitely book Masa's place again when I come back to Japan.