Kōji, nicknamed Kōri-chan, is a youthful ice devil distinguished by her long ice-blue hair, black-blue eyes, and a button nose lacking a visible mouth. Her pale mole-like face contrasts with her light blue kimono, while her physiology produces strawberry-flavored syrup from her blood and lemon-flavored syrup from her urine. Silent yet expressive, she communicates through actions and presence.

As the younger sister of Yusa, a high-ranking ice demon, she collaborates in their seasonal shaved ice venture within the human world. Her days intertwine with recurring confrontations: Mei Tachibana, a police officer, obsessively kidnaps her, captivated by her innocent charm, while Yurine Hanazono aids her in countering Jashin-chan’s antagonism.

Kōji harbors simmering defiance against those who mock her low-class status, retaliating fiercely when provoked, as seen in clashes with Jashin-chan. This resolve underscores her refusal to be diminished by others’ perceptions of her youth or fragility. Her narrative role weaves resilience into comedic chaos, balancing supernatural absurdity with her persistent navigation of Mei’s fixation and rivalries among demons. Relationships and situational conflicts anchor her presence in the series, framed by her distinct traits and the whimsical yet combative dynamics of her world.