Noriko Nakajima is a fifth-grade student in class 5-3 at Domori Elementary School. She is portrayed as a sweet, gentle, and notably calm girl who stands out among her classmates for her relatively ordinary and well-adjusted nature. Unlike some of her peers, she does not actively seek out trouble, though she frequently becomes involved in supernatural incidents regardless. She has shoulder-length pink hair and is recognized as a bookworm with a fondness for animals. Academically, she performs well and demonstrates a clever, tactical mind, as seen in situations that require careful reasoning. Her natural demeanor is quiet and laid-back, but she can occasionally reveal a more playful or spirited side when influenced by unusual phenomena.

In the story of Jigoku Sensei Nube: Kyōfu no Natsu Yasumi! Ayashi no Umi no Densetsu, Noriko joins her classmates and teacher Nube on a summer trip to a southern island. Her role is primarily as a supporting member of the group, and she is present during the events surrounding the legend of the sea spider. Her motivations are simple: she wishes to enjoy the holiday with her friends and remains a dependable presence among the group. She does not drive the plot forward on her own but contributes to the collective dynamic of the class.

Noriko shares a close friendship with Shizuka Kikuchi, and the two are often seen together. She also maintains generally positive relationships with her other classmates and with Nube. A notable dynamic exists with Miki Hosokawa, who sometimes feels overshadowed by Noriko's innocent charm and physical attributes, leading to mild jealousy. Throughout the series and into this film, Noriko develops from a background character into a more prominent and reliable member of the class, though her core personality remains consistent. She possesses no supernatural abilities of her own, relying instead on her intelligence, composure, and the protection of those around her when facing danger.