Apparently Nick Sugar and his boxing brother, Dan, were born "Shugar," and changed their last name to "Sugar." They were of Greek heritage, per the November 23, 1917 Tacoma Times. 
His last-known amateur bout occurred October 13, 1914, Everett, WA, USA, against Travie Davis. The Everett Morning Tribune gives only their last names and, although it mentions the card the morning-after, it did not provide the results. The Everett Daily Herald reports that Davis won the decision here. (Bout staged at Liberty Hall, located on Rockefeller Street between Hewitt and California, and sponsored by the Teamsters Union.) The last name of Davis' opponent is given as "Shugar," "Shugart" and "Schuchart" by various editions of that paper (announcing the card, reporting the morning after, etc.). This is believed to be Nick Sugar. Davis and Sugar became friendly sparring partners, according to later editions of local papers. In fact, in mid-1917 one Everett paper reported that Davis, then fighting in Ohio, had written that he missed sparring with Nick.
By late 1932, perhaps starting earlier, Sugar operated the Totem service station at California Street and Wetmore Avenue, Everett. It had a complete automobile servicing plant. He was a machinist by trade (as early as 1923, according to an Everett Daily Herald newspaper account).