Kozue Nishimori works part-time at the Everymart alongside other characters. She maintains a consistently congenial demeanor and often stands very close to others during interactions, a habit that sometimes leads others to misinterpret her intentions. She is adept at fostering relationships across various social circles.

Her interest in fishing stems specifically from her feelings for the person she likes. In episode 5, she explicitly reveals this person is Hana Ayukawa, stating she started liking fishing because of her feelings for Hana. This confession prompts Hiro to question what she means by "like". Later in the same episode, while Hiro is being scolded by Tsutsujimori for overspending, Kozue takes the opportunity to hug Hana's arm.

Kozue displays a particular fondness for Hana, frequently finding herself in Hana's company and attentively shadowing her activities. This reinforces her role within the group dynamic centered around fishing and the convenience store workplace.

Her birthdate is documented as March 26th; her precise age remains unspecified.