Kōji, also referred to as Kōri-chan, is a recurring supporting character in the Dropkick on My Devil! series, including the television special Dropkick on My Devil!!: Apocalypse Day. She is typically seen alongside her older sister Yusa. Kōji has long ice blue hair and black-blue eyes, with a button nose and no visible mouth. She wears a very light blue kimono. Her personality is not extensively detailed in the source material; she generally appears as a quiet, understated presence who accompanies her sister during their appearances. Her motivations are not elaborated upon, and she does not undergo significant development, as she remains a minor background figure in the larger cast. Her role in the story is that of a recurring extra, often involved in group scenes or brief comedic interactions with the main characters. In Apocalypse Day, she is listed among the supporting characters, suggesting she appears in the special but does not drive the plot. No specific supernatural abilities have been described for her, though her ice-themed design may hint at a thematic association with cold or water, but this is not confirmed in the available information.