We stayed at Hiro's place as a family with 2 little kids for 2 weeks. It's small but cozy. We had an extra futon on the floor and had enough room for a separate bed room and living room (where we as parents could stay up while the kids were already asleep). The apartment heats up quickly in winter but the toilet + bathroom are quite cold. I sometimes wished for a heated toilet seat..it was OK though.
Unfortunately, the washing machine didn't work even though it was on the listing before. Hiro admitted he forgot to mention it was broke and gave us a discount on the price (thanks again!!). Luckily there is a coin laundry almost across the street (don't even need detergent there). Also, there is a 7/11 down the street as well as some super markets such as MyBasket, Donki, Keikyu Store in walking distance. A nice green and fun park completes the surrounding area. Only a short walk and you're at a small beach + some playgrounds - we recommend the Omori Nori museum (for free).
A cozy Airbnb!