Miko Kamiyama lives with her father at their family temple, serving as a shrine maiden. Her conservative family enforces strict rules, forbidding meetings with the opposite sex and imposing an afternoon curfew, severely limiting her social freedom.

This sheltered upbringing makes Miko somewhat naive and inexperienced in relationships. Though cheerful and kind, she appears unworldly. Her innocence is notable, often accompanied by clumsiness and social awkwardness that lead to mistakes or seeming slow to understand.

She shares a close friendship with her classmate, Mizuho Yuuki. Miko harbors romantic feelings for another classmate, Tohru Nagase, but struggles to confess due to shyness and her family's restrictions. She turns to Mizuho for help navigating her feelings and interacting with Tohru, who lives temporarily with Mizuho's family.

Her romantic interest becomes complicated when an underclassmate, Ai Minamizato, also pursues Tohru. This creates a situation where Tohru faces a choice, potentially straining Miko's friendship with Mizuho due to their shared affection.

Miko is 17 years old. She has olive-colored hair, violet eyes, and stands 1.56 meters tall. Her blood type is A, and her birthday is January 18.