Lucinda Lancaster, a ten-year-old orphan recently adopted by the cold Lancaster Earl and Countess, endures a lonely birthday breakfast, feeling unwelcome despite her gratitude for the basic necessities. A harsh comment from her adoptive father, stating her adoption was out of necessity, triggers a vivid memory of her past life as Sakurai Rumi, who died at fifteen in a car accident. Lucinda realizes she has reincarnated into a world of magic, a concept that excites her as a former fantasy RPG enthusiast. Determined to live a life of adventure rather than mere survival, she sets a new goal: to become a magician and embark on a journey.
Her immediate "job" in this new life is to resolve her adoptive brother Chris's hikikomori (shut-in) problem. Chris is deeply grieving his deceased younger sister, Maria, whom Lucinda was adopted to replace due to their similar appearance and magical aptitude. Lucinda's initial attempts to connect with Chris are met with cold rejection, but a heartfelt apology from Lucinda, acknowledging his grief and Maria's irreplaceable presence, prompts Chris to open up. He reveals his despair over his parents' callousness towards Maria's illness and death. Lucinda, empathizing with his pain from her own past loss, comforts him and suggests they leave the house and travel together when they are older. This conversation marks a turning point, lifting Chris's spirits and forging a genuine sibling bond between them. Chris soon emerges from his room, and their relationship flourishes.
Shortly after, Lucinda receives an unexpected invitation to a royal tea party hosted by First Prince Aaron, an event intended for finding future engagement candidates. Despite her mother's insistence on securing a good match for the family, Lucinda, supported by Chris, attends with the sole intention of enjoying the refreshments and avoiding any romantic entanglements. At the tea party, Lucinda is seated next to the kind and charming Prince Aaron. Uninterested in the competitive "prince-hunting" among the other noble ladies, she candidly expresses her dream of becoming a magician and traveling the world. Impressed by her unique ambition, Aaron offers to introduce her to a renowned magic teacher, Flora Trevor, a Viscountess. Lucinda eagerly accepts, believing she has successfully diverted any engagement prospects.
Lucinda begins her magic lessons with Flora, who quickly discovers Lucinda possesses strong magic with an affinity for all elements, particularly lightning. Flora notes a "lid on her heart" that needs to be opened for full magical potential. Lucinda's vivid imagination, honed from her past life's gaming, proves invaluable in spellcasting, allowing her to quickly master basic wind magic. During one lesson, Lucinda encounters Flora's son, Ray, a rebellious Royal Magic Academy student who disparages magic teachers. Lucinda, defending Flora and the teaching profession, helps Ray reconcile with his mother and inspires him to embrace teaching. Ray subsequently joins Lucinda's magic lessons.
Later, while exploring the town, Lucinda meets Lyle Maclean, the son of the Prime Minister. Lyle confides his dream of becoming a knight, which his father opposes due to his perceived lack of talent in swordsmanship, despite his strong magic. Lucinda, drawing on her own experiences, encourages him not to give up and suggests he become a "Magic Knight," combining his magic with combat. Lyle is inspired, deciding to pursue this new path and propose it to his father.
Five years later, a fifteen-year-old Lucinda enrolls in the Royal Magic Academy. She reunites with Aaron, who remembers her fondly, and Lyle, who reveals that the "Magic Knight" concept, now a crucial part of the Royal Guard, originated from her suggestion. Lucinda is surprised by the far-reaching impact of her casual advice. In her "Special Magic Class," she discovers Ray is now her homeroom teacher. She then meets Mia Brooks, a beautiful girl who claims to be her friend and reveals that their world is actually an otome game called "Love and Magic Academy Paradise" (KoiPara). Mia, the "heroine," informs Lucinda that she is the "villainess" and that her actions have already drastically altered the "original story," changing the personalities of Aaron, Lyle, Chris, and Ray (all "capture targets"). Mia, a "dream girl" who enjoys observing romance, offers to help Lucinda navigate the game's plot, including a "final boss battle" involving a demon king. Lucinda, initially overwhelmed, agrees to be friends with Mia, now determined to pursue her magic and, perhaps, even participate in the game's climactic battle.
