We regret that we couldn't give this place the 5-star like the other travellers here. We were greeted with a musky smell of mould from the entrance which was also felt in the house. Though generally the place was clean, it didn't feel 100% comfortable because of the musky smell and we had to use the air conditioning all the time. Our clothes also ended up absorbing the smell, especially our jackets that we placed in the wardrobe. Understandably the weather in Tokyo was very hot and humid and the place is on ground floor, but it is definitely a concern for those who are a little more sensitive or are asthmatic. Perhaps this is not an issue in winter. The lighting also didn't feel as airy and bright as the pictures but this is only minor.
Otherwise, we felt the location was really nice. There's a cute Shiba dog in the neighbourhood and a lovely street full of small shops and restaurants with a local feeling which gave it a nice experience walking to and from the station everyday. It was very easy to navigate around Tokyo with Hatagaya station - with a bus stop nearby that takes you directly to Shibuya and Shinkjuku. It's also close to Shimokitazawa (around 30 min walk), a nice location for second hand clothes shopping, cafes and bars.
It was also convenient that the wifi in the house was a pocket wifi device that we could use outside. Though the battery was quick to burn out. Luckily there's lots of wifi at the main stations for emergency navigation needs.
Though we didn't meet Mitsuko as our check-in time was quite early, everything was well organised. We received lots of information prior to our stay which made checking in and finding the place a smooth process.
It's quite a compact space especially for any tall folks (and I wouldn't fit 3 people), but it's fine if all you need is a place to crash at the end of the night.