Kirie is one of Umaru's classmates along with Ebina. She sometimes has an intimidating appearance, but it turns out to be just her scary exterior. Initially, Kirie follows Umaru home after finding her student ID. When she meets Umaru in her "indoor" form, she mistakenly believes that she's meeting Umaru's little sister Komaru and is so enchanted by her cuteness that she wants to serve her as Master. Additionally, Kirie admires Umaru in her perfect form and considers Ebina-chan a rival.