Yuna Yunis is Touka Scott's childhood friend. According to Touka , she has a "seriously idealistic style" despite her scolding and brusque personality; three years ago, she was saved by Shion when she was attacked by a demon, and has admired him ever since. She dreams of adventuring like that hero, and when Shion dies in an accident and she realizes that his body contains Touka's spirit, she immediately decides to embark on a journey with him.
She also used to long to be a magician and even made a costume and called herself 'Magical Girl Yunalin', but this has become bad history for her. Her current magic level is only '2', the same as a child's, so she handles physical combat in normal battles. However, she has an extremely stronger magical power than her body.
Only when certain conditions are met does she assume the costume of Magical Girl Yunalin and her magic level reaches level 50. At first, she looks at Touka with disdain, but on her journey she comes into contact with his despair and ends up changing her feelings towards him, becoming aware that he is of the opposite se.x.
Source: Manga