There were at least two locations under this name. This one, owned by James and Robert Lee, was located on Winter Street in Waltham, Massachusetts, next to a cinema, and lasted roughly from 1975 - 1990.
It could be found taking exit 48 off Route 128.
They advertised Chinese and Polynesian food and cocktails (in a separate cocktail lounge with dress code).
This space apparently later housed The Winter Street Cafe, which changed its name to Sato and closed in 2015. Umi opened at this location later that summer and is still in business as of 2025.
Exiting 34 off of Route 128 would take you to the second Lanai Island location at 147 Lowell in Wakefield -- which advertised outdoor dining as a unique feature.