The place is really nice and safe, everything you need for a short stay is available. It was very clean when I arrived and can recommend the place to all travellers...
Setagaya is a very nice area and convenient location, just a short walk from Yoga Station is the place and easy to find, everything is as it is described.
Shops like 7/11, Lawsons are just a few minutes walk...Gian Franco bakery is great taste and everything you may need is easy to get in the area.
A quick tip if your traveling with many/heavy luggage’s or want less transfers, from Haneda Airport take the Limousine Bus to Futako-Tamagawa Station, from there it’s either a one stop ride by train to Yoga Station or take a taxi which is a 6-7 minute ride and costs around 1.600YEN.
From Futako-Tamagawa Station you can also get the same Limousine Bus to Narita Airport.