We (my girlfriend and I) loved staying with Kotaro san and Kei san. We were their first guests in their new house, which is absolutely nice, cosy and very modern. The location is very convenient - about 10 minutes walking from Nishi Nippori JR Station. From there you can take the Yamanote Line to Ueno, Shinjuku and Tokyo Central Station. The bedroom where we stayed is nice and the bed even has a matras heater :) Kei is a lovely and warm person and Kotaro is really funny. Both of the are nice to chat with and very helpfull. Kotaro even walked with us to the railway station to help us carrying our heavy luggage. Kero is so cute and great to play with. Every morning Kei cooked Japanese breakfast for us, which was delicious. One night we had dinner together - Japanese hotpot :) Overall it was a unique experience to stay with Japanese locals. If we will come to Tokyo again, we will stay with Kei and Kotaro for sure!