Osaka OS-Aster The Osaka OS-Aster has a modem design with slick line, a comfortable feel, and wide range of settings and capabilities. The OS-Aster can massage you from neck area to flutes and upper hamstrings with S, L= Rack roller. O-Aster has 5 massage style (Kneading, Knocking, Tapping, Kneading lapping and Shiatsu) that makes you completely relaxed.