Yui Mitosagi is a character in Exist Archive.
Yui is a kind young woman who loves children. She was raised in an orphanage where she dreamed of becoming a special effects actress. Her wish was to become a hero that will fulfill her dreams and the dreams of children everywhere. She makes occasional appearances at the orphanage dressed like a hero, and is extremely popular with children. While performing in a hero show on the roof of a department store, she gets summoned to the planet Protolexa.