First released by Mieko Hirota (1965).
Also recorded by Dave Pike (1966), Chris Montez (1966), Marvin Gaye (1966).
Hit versions by Bobby Hebb (US #2/R&B #3/UK #12 1966), Boney M. (UK #3/NETH #1/GER #1 1976).
From the wiki: “Bobby Hebb’s breakthrough as a songwriter would be born of tragedy. In November 1963, already upset over the JFK assassination, Bobby then learned that his older brother, Harold, had been stabbed to death the same night in a fight outside a Nashville nightclub. Out of his depression, Hebb began to write. Using past hurts (‘Yesterday my life was filled with rain’) and inspired by the anonymous smile of a complete stranger (‘You smiled and it really, really eased the pain’), ‘Sunny’ came into being.
“The upbeat number was included in Hebb’s nightclub act at his gig at the New York club Brandy’s. The audiences responded positively as did record producer Jerry Ross (‘I’m Gonna Make You Love Me‘), who included the song on a publisher’s demo record that found its way to Japan.
“That was how ‘Sunny’ came about to be first recorded and commercially-released in Japan – not the US – by Mieko ‘Miko’ Hirota, the ‘Connie Francis of Japan’, where it was said to have done well on the charts.