Wada Hiroshi and His Mahina Stars made some really wonderful ballads.
Lush strings, slide guitar and acoustics led by a chorus of well trained vibrato!
I've been unable to track down a full length, but here is a compilation of 9 singles spanning a decade (1956-1966) in chronological order.
Beautiful and haunting.
Get it here.
Here's a video of the Mahina Stars, reunited in 1985: