Sylphia Harvest endures a life of quiet abuse as an "ornamental" Saintess, filling in for the absent Marielianne Honeydeil. Kind-hearted and humble, Sylphia diligently receives offerings, often dismissed by nobles like Sir Curtis, and offers sincere, simple prayers to the Earth Spirit Valtis and Sky Spirit Titia. From the fallen Harvest family, once a lineage of Saintesses, she fears angering the spirits. Marielianne, engaged to First Prince Antonio Gimlet, is vain, selfish, and cruel, using her position for personal gain and constantly reminding Sylphia of her "fake" status. Antonio, doting on Marielianne, confines Sylphia to the temple without food, using her as a scapegoat for Marielianne's neglect.
Second Prince Lute Gimlet secretly visits Sylphia, bringing her food and expressing concern. He notes that Sylphia's genuine connection has inspired commoners to visit the temple. Sylphia, feeling a stronger spiritual presence, experiences a dream-like encounter where Valtis and Titia manifest. They thank her for her sincere prayers, declare her the "true Saintess," and grant her power, revealing their complete ignorance of Marielianne or the Honeydeil family, who supposedly held the title for a century.
Waking with newfound power, Sylphia inadvertently causes discarded roses to rapidly grow and cover the temple, a miracle that spreads her fame. Marielianne returns in a rage, violently attacking Sylphia. Sylphia's desperate wish to stop the assault triggers an uncontrolled burst of spiritual wind, throwing Marielianne across the room. Fearing her power, Sylphia is distraught, while Marielianne vows revenge.
Lute comforts Sylphia, affirming his belief in her. He offers her an escape, suggesting she stop praying to lose her power as Antonio is about to marry Marielianne, ending Sylphia's role. However, Sylphia, touched by Lute's selflessness, resolves to embrace her true Saintess role, connecting people and spirits.
Her first mission takes her to a blighted village, where she discovers a "black miasma" emanating from the local lord's mansion, invisible to others. Sylphia uses her power to heal the fields, causing crops to flourish and villagers to rejoice, further solidifying her reputation. She expresses her desire to travel as a commoner, teaching people about spirits, and Lute agrees.
Meanwhile, Marielianne manipulates Antonio, accusing Lute of conspiring with Sylphia to usurp the throne. Antonio, swayed, agrees to have Sylphia executed. The King, pressured by Antonio's threats and his own past complicity, reluctantly consents.
However, Lute brings Sylphia to the King to present her as the true Saintess. Sylphia sees the black miasma clinging to the King, confirming deep corruption. The King, misinterpreting Lute's protective stance, orders Sylphia's arrest. Sylphia's wish to protect Lute causes Valtis and Titia to physically manifest, dispelling the miasma and confirming Sylphia as their chosen Saintess, while denying any knowledge of Marielianne.
The King, realizing his machinations are exposed, is forced to confront the truth. He kneels before Sylphia, begging her to marry Antonio to save the kingdom, promising to restore her family. Lute vehemently exposes the King's and Honeydeil family's century-long corruption: they colluded to steal offerings and suppress the Harvest family, leading to the spirits' isolation. As Lute speaks, miasma leaks from the King, which Valtis explains is born from betraying and neglecting spirits. Valtis warns the King that his heart is full of miasma and he will not live long unless he changes his ways. Sylphia is left to ponder the King's desperate proposal amidst these shocking revelations.
