I had the address so it should be easy for me and a native Japanese to find. I've done business with Japanese people and wondered what their addresses really mean. Today I found out. Ku means district and there are 23 districts in the city of Tokyo. Shinju was the district we were looking for.
Every district has smaller divisions called wards.
The ward we were looking for was Nishi. The wards are broken into smaller divisions. The first 1 of the numerical address is that division. So in the Shinju district we were looking for the ward Nishi 1. A further division is the second numerical address 11 and the last numerical 1 is what we think of as the street address.