An accident has taken his entire family from him. His remaining family, his pet cockatiel, has also passed away due to old age.
Overwhelmed by grief, he drops out of school, holing himself in his apartment. And yet, this reoccurring dream that he—Yamagata Tatsumi—keeps seeing… Is there a meaning to it?

One day, Tatsumi finds himself forcibly summoned to another world. As he opens his eyes, the Holy Maiden he sees in his dreams stands before him.

“Master!! It’s me!! I’m Chiiko, your pet!!
“Huh? Chiiko…? The cockatiel I used to keep…?”

And thus starts the story of a boy who keeps the Holy Maiden as his pet…or not. It is the story of the reincarnated cockatiel who’s now known as the Holy Maiden, and her former owner, a boy who later becomes an exorcist with the epithet “Heaven Soarer”