Tomoyasu Hotei is a japanese guitarist and is well known as a big RM fan. He joined RM as a guest guitarist when they played at Fuji Rock Festival and he played last three songs with them.
http://www.myspace.com/hoteiHe started to play guitar when he was 14 and his band played RM songs when he was a high school student. Later he formed a band called BOΦWY and succeeded as a professional musician. After he disbanded BOΦWY he made some solo albums. He and Andy have long-standing friendship since when Andy joined one of his solo recorded in London. By andy's help Hotei realized his dream last saturday.
We can see some photos from their live and backstage at link below.
http://www.hotei.com/blog/