From what is known, Klaha's musical career began in 1993 when he, still known by his real name, Haruna Masaki, joined with Atsushi Fukuyama and Masanori Ito to form Pride of Mind.
Though the future looked bright for the new wave/electronica band, Pride of Mind suddenly broke up in 1996 after releasing only one album. It is still unknown exactly why the members decided to part ways.
Masaki disappeared from the music scene for several years before returning in the late 90s. Taking the name Klaha, he became a support member for Malice Mizer and was asked to supply the vocals for the band's Bara no Seidou album when their vocalist at the time, Gackt, decided to leave the band. It wasn't until after the release of the album, and Klaha had performed with Malice Mizer a few times, that he officially became the band's new vocalist. With his elegant, operatic voice, Malice Mizer's style became decidedly darker and more gothic.
Klaha didn't get to enjoy his new role for long as, not even a year following his becoming an official member of the band, Malice Mizer decided an indefinite break in December 2001.
This time, however, Klaha did not disappear from the music world. Instead, almost exactly a year after Malice Mizer's break, he released his first solo album, Nostal Lab, his solo work falling on the opposite sound spectrum to that of his previous band's. Songs from the album, as well as from his Märchen single, show off Klaha's pop side while still exhibiting the same clear and elegant sound he was known for in Malice Mizer. At times strong, at others delicate, his sound is versatile and represents the wide range of his musical inspirations, each song a unique creation consisting of Klaha's beautiful lyrics and his undeniably amazing voice.
The release of Märchen was accompanied by a few short live tours and in-store appearances, though this also marked a quiet period for the artist. He went into a sort of seclusion for about a year before releasing a new mini-album, Setsubou, in early 2004, though this hardly signified his return.
In mid-2004, Klaha's fan club was closed and he once again vanished, illness being cited as his reasons for not continuing to sing.
Since then, only rare updates have appeared on his official site, usually occurring around holidays, such as Christmas. In December 2006, it was stated that Klaha would resume activities in 2007, though there are still no signs of his return.