From the earliest days, people of Slantania have lived beneath a veil of miasma, a force that summons monsters wreaking havoc across the realm. When the kingdom"s Order of Knights can no longer restrain these beasts, the Grand Magus calls upon a holy maiden—the fabled "Saint"—to annihilate the fiends and bring peace back.
One evening, after a long day at her job, Sei Takanashi is drawn by a mystical power into another world. She arrives in the kingdom of Slantania and learns that the Grand Magus has accidentally summoned two Saints—Sei herself and a brown‑haired girl. Since only one holy maiden is needed, the prince designates the other as the Saint, leaving Sei to fend for herself.
Sei directs her attention toward the Medicinal Flora Research Institute, a place renowned for its herb and potion studies. While pursuing her new interest, she encounters the commander of the Third Order of Knights. Little does she realize that her Saint abilities will continue to shape her new existence.
