Maintaining engagement is challenging in human-human interaction. When disengagements happen, people try to adapt their behavior with an expectation that engagement will be regained. In human-robot interaction, although socially interactive robots are engaging, people can easily drop engagement while interacting with robots. This paper proposes a multi-layer re-engagement system which applies different strategies through human-like (non-)verbal behaviors to regain user's engagement taking into account user's attention level and affective states. We conducted a usability test in a robot storytelling scenario to demonstrate technical operation of the system as well as to investigate how people react when interacting with a robot with re-engagement ability. Our usability test results reveal that the system is potential to maintain user's engagement. Our selected users through open-ended questions gave positive comments to the robot with this ability. They also rated the robot with re-engagement ability higher on several dimensions i.e. animacy, likability, perceived intelligence.