In this paper, we report our studies on sliding friction of soft and sticky polymer gels. When the gel is slid against a rigid substrate, formation of pulse-like detachment waves is observed, and the dynamical patterns of the detachment waves drastically change with the sliding velocity. Through simple visualization techniques to observe the stick-slip motions occurring at the interface, we succeed in characterizing the sliding behavior. We discuss the importance of visualization and meso-scale description of the phenomena.