A member of a mysterious group that appeared from nowhere... the Sirens. Among them, Purifier is very prudent in attaining the group's "goal." She has an aloof, holier-than-thou attitude. For some reason, she is upset over the peace in this world. It's no wonder she would try to cause a stir during the Joint Military Exercise. She's working on some kind of plan, but will it succeed?
Purifier receives an invite from a certain famous idol. "What is she thinking? No, wait... Maybe she isn't thinking at all..." Purifier must make a choice that she never thought she would ever have to make.