Being a second semster senior is what Athena and Jihye have dreamed about since their freshman year at Elements High, the best element training high school in the world. During the second semester is when they'll be placed into their mission groups. These groups take the remainder of the senior year to train and then are released into the world to fight off demons or fight against people who abuse their element's power.

Athena's one of the best students in her class and the teachers have been waiting for this class to graduate for a while now. The Striker group, an extremely dangerous mission group has been on the rise and there seems to be a brilliant pairing of students in this class involving Athena. What happens when this group includes with a human she has despised for years. Will she be able to assimilate to her new life? Or will this human be too much for her to handle?