Tetsuya is the leader and bassist of the rock band L'Arc~en~Ciel. Formerly known by the stage name tetsu, on December 1, 2009 he started to use his birth name.
He also does backup vocals in L'Arc~en~Ciel and has composed many of the band's songs, including "Link", "Ready Steady Go", "Finale", "Driver's High", "Stay Away", and "Pieces". In 2001 he started a solo career under the name TETSU69 (1969 is his birth year). On November 26, 2006, he released one song under his old stage name, and as of December 10, 2009 he uses his birth name. From 2005 to 2006 he was a support member of, Dead End front man, Morrie's solo project Creature Creature. In 2007, he married 22-year-old actress Ayana Sakai.
tetsuya plays with a melodic style. Many of L'Arc-en-Ciel's songs involve him playing counter melodies with guitarist Ken while still holding a groove with the drums. tetsuya's composing can be seen as more "poppish" as compared to Ken's who has a heavier and sometimes bluesy approach. He frequently uses slides, hammer-ons, and pull-offs in his playing.
He plays with a pick most of the time, but uses finger style occasionally when the song calls for it, such as in "Winter Falls" and "Jojōshi". In a few songs he can be heard using the slap style of playing, such as in the L'Arc songs "The Nepenthe's" and "Twinkle, Twinkle'. tetsuya has also used distortion, such as in "Stay Away" and "Butterfly's Sleep".
tetsuya primarily plays a 5 string bass since L'Arc-en-Ciel's 15th anniversary, but is known to occasionally use 6 strings. Such as in "Neo Universe", "Time Goes On", "Get Out from the Shell" where he plays lead melody. In "Perfect Blue" he used a 6 string baritone guitar (an electric guitar between the range of a bass and standard electric guitar). tetsuya also uses a guitar/bass double neck in the song "Trust".
Even though tetsuya is endorsed by ESP Guitars and has several signature models, he has used his Zon bass for most of his recording work. tetsuya is an avid collector of basses and guitars, owning over 120 basses and more than 20 guitars.