After suddenly being transported to another world in the body of a young girl, Sara gets taken in by a Hunter named Nelly. The two of them live a peaceful(?) life until the day Nelly vanishes, leaving Sara to fend for herself. Sara makes her way to the town of Rosa, where she meets her first friend and joins the Hunter's Guild. Her search for Nelly continues all the while until, at long last, the pair is reunited!

They've now returned to their life on the Dark Mountain, occasionally coming into town. It is on one such visit that Sara encounters a fellow Invited, a boy named Haruto—and their meeting will change the lives of everyone around them.