His album of cover versions of Japanese pop tunes is rising on the charts. And the crooner is scoring on this nation's equivalent of "American Idol," being billed as a genius who understands the musical soul of Japan.
His success highlights a music industry that's still booming, and increasingly eager to internationalize. It's even ready to eclipse the U.S. music world, where CD sales have plunged with the arrival of digital technology.
Hart, 29, says he is living his dream. And he doesn't mind a bit that his fame has come so far from home.
"I am a part of the J-pop world now," he said in a recent interview, using the term for pop music in the world's third-biggest economy.
Hart has won over Japan by focusing on adaptations of local hits such as "Home," a 2008 ballad popularized by singer Yusaku Kiyama about the joys of becoming a father.
Hart's rendition, released as a single in May, surged to No. 13 on the Oricon music charts, Japan's equivalent of Billboard. A month later, Hart released his first album, "Heart Song," which reached third on Oricon.
That's saying a lot, given the size of Japan's market.
Japan's music industry is estimated at $4.42 billion, closely trailing the U.S. at $4.48 billion, although Japan has less than half the population, according to the International Federation of the Phonographic Industry, which tracks such data.