I only recently found out about this singer while look through Neosoulcafe.com. A Japanese Neo Soul singer with an awesome voice.
Being in Japane it’s very difficult to imagine Japanese with really soulful voices, although there are a few around, but they tend to be more underground. The technique of singing for Japanese traditional music such as Enka is very different to western soul music and many young Japanese do struggle to get the correct soul property in their voice. However, I guess it depends on you upbringing, our surroundings and your musical exposure.
Check out her site here – http://naoyoshioka.com/ and a video.