Kuromarimo serves as a loyal subordinate to Wapol, the deposed king of Drum Island, operating alongside Chess within Wapol's retinue during the effort to reclaim the kingdom. Following Wapol's exile after the Blackbeard Pirates' invasion, Kuromarimo maintains unwavering allegiance and engages in hostile maneuvers against the Straw Hat Pirates and Drum Island's populace. When Wapol and his brother Musshuru advance up the mountain toward Drum Castle, Kuromarimo and Chess accompany them. During the castle confrontation, Kuromarimo is unexpectedly neutralized by Musshuru's poisonous spores prior to the battle's climax, an incident that simultaneously incapacitates Chess and eliminates both from the remaining conflict.