In addition to music, Tachibana also launched an acting career and has appeared in television dramas such as Ohitorisama and Mattsugu.

[3] In addition to Tachibana's activities in W-inds, he launched a solo career, with his debut single "Michishirube" releasing on 18 October 2006.

Following its success, Tachibana's second single, "Friend", was released in May 2007 as the first opening theme song to the anime Blue Dragon.

In 2007, Tachibana voiced Prince Arthur in the Japanese dubbed version of Shrek the Third, as his first starring role.

[7] Late in 2012, Tachibana announced his intent to restart his solo career, this time under a mononymous, romanized stage name, Keita.