We have stayed with K-Family before, and like always, a 5-star experience everytime. You get more than a beautiful, clean, and unique space combining traditional with modern Japanese design, but a memorable experience overall because of the hosts and the vicinity. The hosts are very thoughtful & very accommodating. The amount of care they put in there rentals and their guest needs go above and beyond. This residential neighborhood is great if you like quiet evenings, and definitely good for families with kids. If you like urban exploration or older neighborhoods with character, this neighborhood doesn't disappoint and is amazing to photograph especially around dusk.
My only advice to other travellers considering staying with K-Family is that they're not central Tokyo, but east of. If you seek immediate big lights, big shopping malls/arcades, and the crazy crowds, like Shibuya or Roponggii, you will have to plan a train(s) to reach these places. But again, Tokyo has one of the best train systems in the world, and from K-House your a walk away from a major rail line. This said, if you are a seasoned transit traveller or ambitious, taking the train is easy with a bit of planning which your hosts can help you with.