"Big 4 University Championship"

I was looking at some old copies of Black Belt magazine and came across the instructor listing for Kiyoshi Shiina which states he competed in the 1956 Big 3 University Championship and the 1958 Big 4 University Championship. Anyone familiar with this competition? Which Universities would have been involved?

http://books.google.co.uk/books?id=KdkDAAAAMBAJ&pg=PA53#v=onepage&q&f=false