Mitsuo Horiguchi (1908-1990) was a U.S. amateur Go player. He served as President of the New York Go Club? in the early 1970s.
Horiguchi was Executive Director of the Nippon Club starting in 1955, and in 1965 he founded the Nippon Employment Agency. 
 "Mitsuo Horiguchi: Club Director, 82." New York Times, 22 January 1990, Section D, p. 10.
(Dieter: I found it so hard to give this page a proper backlink that I wonder if we should have this page at all)
I am Mr. Horiguchi's grandson and I respect that this page was made for him, please keep it up. Regarding Go, my father told me Mitsuo used to play at the house with a man named Harry Gonshor (math professor). You can see his link here
Mitsuo was also ranked if I am not mistaken. Here is a link stating his importance to the New York Go Club. https://www.usgo.org/sites/default/files/ejournal_archive/20080623/20080623.htm https://www.usgo.org/news/2021/10/50-years-ago-october-1971/
Please feel free to delete, I just wanted to reach out to express my gratitude about my late grandfather.