Dokin-chan is an orange-red germ character distinguished by green eyes, a white face marked by small red cheeks and nose, pink shoes, white hands, a single antenna, and a long tail. Her germ-like appearance remains consistent across all media.

She operates as Baikinman's partner in antagonism, exhibiting a consistently selfish, demanding, childish, and greedy personality. She frequently bosses Baikinman around, compelling him to fetch desired items or people, yet flees when confrontations turn unfavorable. Despite this self-serving nature, she displays underlying kindness, primarily directed towards Shokupanman, for whom she harbors an intense and persistent romantic obsession. This infatuation drives extreme actions: elaborate schemes to capture his attention, decorating her living space with his merchandise, and vivid daydreams of mutual affection. Her fixation sometimes leads her to prioritize Shokupanman's safety over Baikinman's schemes.

Her relationship with Baikinman blends surface-level rudeness with implicit care, forming a dynamic where she exploits his loneliness while maintaining an unspoken bond. She also engages in a rivalrous relationship with her younger sister, Kokin-chan; their conflicts often arise from competing affections for Shokupanman, though they intermittently exhibit typical sisterly camaraderie.

Historically, Dokin-chan wielded a specialized staff with dual functions: one end enlarged objects, the other reduced them. This tool appeared sporadically before being phased out. She pilots a pink UFO for transportation, typically using it for non-combat tasks like carrying items or hostages, with minimal use in direct confrontations.

In "Kirameke! Ice no Kuni no Vanilla-hime," Dokin-chan participates in Baikinman's initial antagonistic efforts against Princess Vanilla's kingdom. Her involvement aligns with her established role, supporting Baikinman's plans while prioritizing self-interest, and does not drive significant plot developments or introduce new character dimensions.