Dokin-chan operates as Baikinman's secondary antagonist partner. She sports an orange-red germ-like body with pink shoes, white hands, green eyes, a single antenna, and a long tail like Mushibaikinman. Her white face features small red cheeks and a nose, marked by an orange line extending to her nose.

Her personality blends selfishness, demanding behavior, childishness, and greed, occasionally revealing underlying kindness. She possesses intense self-regard, convinced she is the world's cutest person. She frequently bosses Baikinman around, demanding food, items, or people, though latent care for him exists. She typically flees first when confrontations turn sour.

She maintains an obsessive romantic fixation on Shokupanman after their first meeting. This fuels extreme actions like elaborate schemes to win him, constant daydreaming, and a room filled with his posters and plush toys. Her relationship with younger sister Kokin-chan fluctuates between camaraderie and rivalry, primarily over their competing affections for Shokupanman.

She once wielded a specialized staff with ends that enlarged or reduced objects, though its use was limited before discontinuation. She uses a pink UFO for transport, often carrying baskets or flowers, and occasionally holding hostages for Baikinman's schemes.

A dedicated movie features her. Her actions sometimes extend beyond typical antagonism, such as collaborating with others during unexpected isolation, though these interactions rarely alter relationships permanently. Her motivations often entwine personal desires—especially concerning Shokupanman—with Baikinman's plots, sometimes leading to independent initiatives that complicate their partnership.