Seon-Nyeo Namgung

Seon-Nyeo is the school's biology teacher. He fought alongside Gyeo-Ul before her death, and now puts on a magical girl dress to help Yeo-Reum and A-Ran retrieve the cubics and protect the school.

In reality, he was the same age as Gyeo-Ul and was a classmate of hers. But after her death, he used the magical pin to turn back time 10 times to try to save her, repeating the same year over again with each attempt, and killing his past self in order for his present self to exist in the past. He used magic to forge his documents and become a teacher. Like Yeo-Reum, Seon-Nyeo blames himself for Gyeo-Ul's death.