Rappa functions as a dedicated follower to protagonist Mankichi Togawa, consistently accompanying him and performing a ritualistic trumpet blast to formally commence Mankichi’s fights. This establishes his supportive role in confrontations. His youth prevents active participation in most physical conflicts and major series action, yet he maintains a persistent presence within Mankichi’s group. One instance showcases Rappa delivering a large pot and fish to Mankichi at school after Mankichi faced food-deprivation punishment, highlighting his loyalty and assistance in daily struggles. Identified as one of Mankichi’s earliest and most consistent followers, Rappa operates in a supporting capacity that reinforces group dynamics around Mankichi alongside figures like Ginji Kubo.