Kōme Sakiyama works as a nurse at Jokei University Hospital, collaborating closely with Dr. Inuki Akaya to care for victims of the Great Collapse, including protagonist Chihiro Kamina during his five-month coma. She possesses distinctive long black hair, an eyepatch over her left eye, and thigh-high socks. Her personality presents a contrast: she projects crude behavior and a notoriously brusque bedside manner towards patients, yet simultaneously acts as a moodmaker within the Malthus Church group and exhibits underlying consideration for others, particularly Inuki Akaya.

Her combat abilities manifest through a blood armament that forms a whip with a pointed tip resembling a devil's tail, classified as an enhanced archaic weapon. Activation of her powers visibly changes her eyepatch to red. Despite her stature, she possesses surprising physical strength, documented carrying significantly taller individuals over her shoulder.

Her background includes participation in an unspecified past experiment. This experience fuels her strong personal motivation to fight the ongoing crisis and underpins her partnership with Inuki in seeking methods to revert transformed individuals to their human state. This history also connects to her status as an artificial human creation, considered a "defective life" by another character. Throughout the series, her loyalty to Inuki remains evident as she fights alongside him despite her abrasive exterior; actions confirming her genuine concern for his wellbeing embody the "Jerk with a Heart of Gold" trope.