Magical Gosamjeu

Korean Title: 매지컬 고삼즈

English Title: Magical 12th Graders

Plot
Yeorum Han traumatized by Gyeowul's, her older sister, death. She committed suicide by jumping from her high school's roof top. One day, Yeorum witnesses her male biology teacher in a magical girl's dress fighting giant fish at school. Yeorum recieves her sister's magical girl's item and avoids danger by transforming into a magical girl.

With SATs approaching closer and closer, can she protect the love and peace in this world? A tale about Han-Yurem, who became a magical girl in her 3rd year of high school, and the mysteries that surround her.