Kazuyuki Matsumoto

松本和之 (Kazuyuki Matsumoto / ka-yu), also known as the bassist for rock band Janne Da Arc, is a solo artist from Japan. He released his first mini-album Solid Beat (under his full name) on August 15, 2007, and a second mini-album Solid Beat II on December 26, 2007. He has also released an instructional bass DVD, Real Rock Bass.

In addition to his music, he works as a clothing and jewelry designer with his own label, Solid Beat, in a collaboration with Japanese jewelry maker GIGOR.