Philia Adenauer hails from the Adenauer family, famed for producing Saints in the Kingdom of Ziltonia. Recognized as a prodigy early on, she endured rigorous training that forged exceptional magical prowess and diverse skills encompassing martial arts, medicine, barrier creation, monster research, and agricultural innovation. This relentless regimen resulted in a stoic, emotionally restrained demeanor, often perceived by others as cold or unapproachable. Her lack of expressiveness, especially an inability to smile, drew public criticism and the derogatory label of being "too perfect" and lacking charm.

Her engagement to Prince Julius Ziltonia represented a rare moment she perceived as parental acknowledgment, though her family consistently withheld emotional support. Julius terminated the engagement, deeming her unlikable, and orchestrated her sale to the neighboring Kingdom of Parnacorta under the pretext that they required a Saint following their own Saint's death. Philia complied, believing herself destined for further mistreatment.

Contrary to her expectations, Parnacorta welcomed her with genuine respect and warmth. Assigned supportive attendants—Lena, Leonardo, and Himari—she encountered an environment valuing her contributions without demanding inhuman perfection. Prince Osvalt Parnacorta actively encouraged her to explore personal interests and experience life beyond duty. Through interactions with him and her attendants, she gradually began to understand concepts of rest, personal preference, and emotional connection. This environment fostered her first expressions of happiness and initiated a journey toward emotional openness.

Her family background concealed a significant secret. Philia is the biological daughter of Hildegard Adenauer, the previous Saint and her former mentor, and Kamil, a northern medicine maker who died shortly after her birth. Her uncle, Georg Adenauer, and his wife Cornelia, unable to conceive an heir, kidnapped Philia as an infant. They propagated false claims that Hildegard had suffered a stillbirth, discrediting Hildegard's attempts to reclaim her daughter. Consequently, Philia was raised by Georg and Cornelia, who provided no affection and later favored their biological daughter, Mia. Philia remained unaware of her true parentage for years, believing Mia was her biological sister.

Philia's relationship with Mia Adenauer, her cousin raised as her sister, was profoundly loving and protective. Despite the revelation of their true familial connection, their bond remained central. Mia deeply admired Philia and was devastated by her departure. Learning the truth about Philia's sale fueled Mia's determination for revenge against their family and Julius. Hildegard later formally adopted Mia, legally making them sisters again. Philia eventually discovered the truth about her parentage, facilitated by Mia and Osvalt, leading to a poignant reconciliation with Hildegard as mother and daughter.

Following her relocation and the revelation of her origins, Philia focused on training Parnacorta's new Saint-in-training, Grace Martilas. She continued utilizing her abilities to protect her new home, notably anchoring powerful barriers against demonic threats. Despite finding peace and acceptance in Parnacorta, she maintained concern for Mia's well-being in Ziltonia. She participated in significant events like Mia's wedding and faced ongoing challenges, consistently striving to protect her loved ones and the happiness she found.