For those of you who's asking who the hell is this guy, well, Nickhun is a Thai artist and member of a Korean boy band 2PM. 'We Become One' is his 2008 solo song. I don't know if it is a single or not.
The song sounded like the ones you usally hear in a coffee shop but it's sooo addicting after several repeat and it's a fun song. And the language is Thai.