Sleep Walker are a Japanese jazz quartet featuring Masato Nakamura (sax), Hajime Yoshizawa (piano), Kiyoshi Ikeda (bass) and Tomokazu Sugimoto (bass), respectively, and Nobuaki Fujii (drums In 2000 the 12 inch vinyl Ai No Kawa / Ressurection In 2002). Their sound signature is identified with fat bass, heavy percussion, spiritual-jazz influenced saxophone and free piano improvisation.
Sleep Walker released their debut album Sleep Walker from Especial records. The album won the high acclaim from Jazzanova and Laurent Garnier. In December 2003 Sleep Walker performed for four consecutive nights at the Jazz Cafe in London alongside Pharoah Sanders. They also toured as a headliner act to enthusiastic crowds of over 2000 in Slovenia, Croatia and Austria along with Kyoto Jazz Massive, UFO (United Future Organisation), Chari Chari and DJ Moochy.
In 2004, Sleep Walker released the single The Voyage featuring Pharoah Sanders and in the spring of 2005, they released another single River of love, which was followed by an Especial Records compilation album, Essence of Especial. In 2006 Sleep Walker released their second album The Voyage from Village Again / Especial Records and performed with Pharoah Sanders at the METAMORPHOSE festival in August. The Voyage won Domestic club / Dance album of the year at the ADLIB AWARDS. In the summer of 2007, an album of Sleep Walkers past work, new remixes and new recordings WORKS was released.