Manami's place was clean and provided all the amenities we required - the mobile WiFi was very useful. The location is on the opposite side of the city to Narita but it is close to a JR station and as such within about 20 min to Shinjuku. Koenji was very welcoming and allows you to escape the hectic crowds of inner-city Tokyo. It has plenty of bars and restaurants within a short walk. We particularly enjoyed Beer Engine and found the nearby bakery useful for a handy sandwich. We would definitely recommend.