We've just spent three nights with Kotaro and Kei (and Kero) and we could never ask to be more looked after. We were fed delicious food, had lots of laughs and had the warmest introduction to Tokyo ever. The house is cute and clean and very very quiet and Mejiro district is a nice area with lots of places to eat, nice backstreets and well connected to the Yamanote line. We had such a nice time we'd recommend Kero Kero to everyone.