Miyabi Momoyama is a human classmate and friend of Mana Inuyama in the 2018 anime series. She possesses fair skin, straight dull green hair featuring a distinctive lock hanging between her eyes, and dull violet irises. Her standard school attire consists of a white long-sleeved collared shirt, a medium-length teal skirt, a matching tie, short white socks, and brown-tipped shoes. She adds a light teal long-sleeved jacket over this uniform in colder weather. Her casual outfit includes a yellow-trimmed orange T-shirt with a single horizontal yellow stripe, olive green shorts, and brown strap sandals.

Miyabi first appears alongside Mana during a class tour of a track stadium under construction. When Mana inquires about pillars on the field, Miyabi questions what she means, stating nothing is visible there, highlighting her initial inability to perceive supernatural elements. She reappears walking with Mana and another friend in episode eight. In episode fifteen, she walks home from school with Mana when they spot Kirara Fusano; after Kirara undergoes spirit surgery, Miyabi is among the students surprised by her transformed appearance.

A significant interaction occurs in episode twenty-five. After Mana receives a heartless message from classmate Karin Yamane via the RAIN messaging app, Miyabi discusses it with her the next day and suggests retaliating using a cursed app, which she subsequently downloads for Mana.

Miyabi receives focused development in episode fifty-two. She enters Kinoko's Forest in another world, initially enjoying herself. However, she rapidly ages within the forest, an experience leading her to gain a deeper understanding of her mother's perspective. Her surname, Momoyama, combines the kanji for "peach" (桃) and "mountain" (山), while her given name Miyabi (雅) translates to "elegant" or "graceful".