VOCALOID? I think its the machine of YAMAHA. not a musician.
you must find morning musume ,Gackt and Perfume in Japanese Karaoke place.
I have not been to karaoke lately , but I think you can also find K-pops.
Japanese song’s lyric is shown by Japanese letters (kanji, hiragana and katakana) ,even Korean singers’ songs
some american or british songs are shown by English
some Korean songs are shown by katakana(maybe ,most of Japanese dont read hangle letters)