The young Mizuno Mai is the result of a relationship between a spirit and a human being.

From the beginning of her life, she has been trapped in some mysterious and curious worlds defended by some living beings called "Guardians." Her birth broke god's rules and her grandfather will be chasing her to erase her existence and everything around her as part of a personal revenge. Because of that, and with a bit of help, she will be able to travel to the past, present and future, and grow in a lot of ways to face her fears.

Meanwhile, you will discover more than a simple reason like that. She will fight monsters, demons and a lot of other souls... and a mysterious God is behind all of that. Mai will try to uncover the truth of his strange world.