Rinko Kuzaki is a long time friend of Yuto.
Rinko Kuzaki is Yuto childhood friend and next-door neighbor. She had a very close friendship with Yuto, as she helped him out of his depression when he first moved to Takamiya. She cried along with him when his parents died during their childhood. She also had close feelings for Yuto until Himari and the other girls started appearing, causing her to display tsundere traits as a result of their constant flirting, and suffers from an inferiority complex from their well-large breast (except for Shizuku). Rinko always tends to ruin every perverted moment between them and Yuto and the fact is that Yuto had nothing to with it in the first place. Despite all of this, she still wants to support Yuto to the very end even if he does become a full-fledged Demon Slayer, as she believes the she is the only person good for him due to their long relationship and that all he ever wanted was a normal life.
Rinko Kuzaki is one of main character of Omamori Himari manga series created by Milan Matra. No information about what inspired her creation.
Rinko is always seen wearing two red ribbons in her hair, every year during a summer festival, Yuto would buy her a new pair for her to wear year round and she would tie last year's ribbons to a treebranch. She owns a pet cat named Ranmaru.