Kazuyuki Matsumoto (bassist from Janne Da Arc) born January 21, 1975 in Hirakata, Osaka, Japan, blood type A. Favorite artists include CRAZY COOL JOE (ex DEAD END bassist) and BOOWY. ka-yu is like a brother to yasu, and is characterized by his more Visual Kei look in comparison to the rest of the band members, as well as his love for animals. He is currently working as a clothing and jewelry designer with his own label (Solid Beat) in a collaboration with Japanese jewelry maker GIGOR....

Kazuyuki Matsumoto (bassist from Janne Da Arc) born January 21, 1975 in Hirakata, Osaka, Japan, blood type A. Favorite artists include CRAZY COOL JOE (ex DEAD END bassist) and BOOWY. ka-yu is like a brother to yasu, and is characterized by his more Visual Kei look in comparison to the rest of the band members, as well as his love for animals. He is currently working as a clothing and jewelry designer with his own label (Solid Beat) in a collaboration with Japanese jewelry maker GIGOR. He also released two solo albums (under his full name, Kazuyuki Matsumoto). The albums, named Solid Beat and Solid Beat II respectively, are both mini albums, the lyrics entirely in English. He has also released an instructional bass DVD, Real Rock Bass, and released a photobook, entitled Solid Beat ~Zero~ in March 2008.