He rose to prominence as lead vocalist, guitarist and songwriter of the rock band Ling Tosite Sigure, which formed in 2002.

Released in 2011, the DVD features a photobook and a movie shot on 8mm film that acts as a music video for the three tracks on the disc.

The limited press version featured a live studio session (DVD) of selected tracks from the album directed by P.B.

[3] Kitajima's second release was prefaced by the single "Unravel", which acted as the opening for the popular anime series Tokyo Ghoul and the mini-album Contrast.

[4] The mini-album Contrast was released the same year as "Unravel", being 2014 and featured a live DVD from the 2013 Rock in Japan Festival along with a bonus video filmed in Berlin for the song "Tokio" (limited pressing only).

White Noise, being released in November 2016, featured six new tracks: a reworking of "Like There is Tomorrow", the singles "Signal" and "Secret Sensation", and a proper studio recording of "Jewel of Sin".

[12] Continuing his solo music project, TK, collaborated with Koshi Inaba of B'z at the start of 2022 to release the single As Long as I Love/Scratch on March 26, 2022.