I thought the saxophone credit for Crusher Kimura was a mistake, as she's a violinist, but it does seem like she plays the sax too.
Her profile on some band page says violin and sax, and her
2003 live performance list includes a sax performance by "ヨッシャー木村."
川口佑介 might be Yusuke Kawaguchi (R.I.P.?):
http://akeboshi.blog.so-net.ne.jp/2009-12-23-1