I stayed at Cassandra and Mikoto's place with my girlfriend for 5 nights and we were both extremely satisfied. The room was clean and spacious and the surrounding residential area felt safe to walk around even late at night. There's a small restaurant right next door to the apartment which I would definitely recommend. It appeared family run and not too expensive at all.

Their instructions were easy to follow and we reached the apartment with no issues. I would suggest taking the bus as advised on their guide from Shinjuku station as it stops right down the road from the apartment.
All in all we would definitely stay here again. Cassandra and Mikoto were always quick to respond and are great hosts.