Narumi is an image conscious person who keeps up appearances at work by hiding the fact that she is an otaku from everyone, including her family. The only people who know this side of her are Hirotaka Nifuji, Hanako Koyanagi, and Tarou Kabakura, after Hirotaka outed her by asking if she was going to participate in the next Summer Comiket.

Narumi is described (by Hirotaka) as someone who is always observing other people, being considerate, and making sure they have fun.