Chapters 3 through 12 of the light novel detail the protagonist, Toree, a four-year-old child, experiencing a sudden surge of memories from a past life as an adult office worker in Japan. This awakening occurs when Toree witnesses a heated argument between their mother and a well-dressed woman, Olivia Middleton, who has barged into their humble home. The argument escalates into a physical fight, during which Toree's mother is injured. Olivia, mistaking Toree for the product of her husband's infidelity, is struck by Toree's resemblance to her husband.
A pivotal moment occurs when Toree's mother reveals that Toree is not her biological child, but rather an infant found on their doorstep. This revelation shocks both Olivia and Toree, who had believed they were mother and child. Olivia, a countess from the influential Middleton family, explains that her elderly grandfather, who is sixty-five, is obligated by a magical contract to create a will. This has led to a surge of individuals falsely claiming Middleton lineage to claim his fortune. Toree, with their distinctive sky-blue eyes and potential silver hair, has been identified as a strong candidate for Middleton blood through magical means.
Olivia takes Toree with her, intending to return home. During their journey, Olivia admits to impulsively leaving her carriage in anger, resulting in them getting lost. They are eventually found by a knight named John, who also notes Toree's striking resemblance to his master, the Count. Toree learns that the Count has two sons, aged eighteen and twelve. Upon arriving at the Middleton estate, Toree is initially placed in a guest room but is later moved to a storage room by the fastidious twelve-year-old son, Oliver, who is disgusted by Toree's perceived dirtiness. Toree's past life memories resurface, making them aware of their unusual situation and the potential social awkwardness of their mature demeanor.
The following days see Toree interacting with Oliver and his older brother, Brian. Brian, the eighteen-year-old, initially suspects Toree of being an imposter sent to harm the family, but Toree's innocence and lack of understanding disarm him. Toree also learns that their mother, Jade, is not their birth mother, but rather found Toree as a baby. The Count, while not believing Toree is his child, acknowledges Toree's Middleton blood and arranges for potential fathers to be identified. Toree is moved to a more comfortable room, and the Count's butler, John, ensures Toree is cared for.
The narrative then shifts to Toree's potential fathers. A man named Paul, a muscular knight captain, is identified as a possible father. He is kind and doting towards Toree, even kissing them goodnight. The Count, whose own infidelity is suspected by his wife Olivia, is relieved to find he is not Toree's father. Toree also learns that Olivia is currently away, having been summoned by the Empress Dowager.
The story progresses to the day of the will creation ceremony at the royal capital. Toree, accompanied by Brian and Oliver, witnesses the gathering of numerous self-proclaimed Middletons. A magical test is conducted to verify true lineage. Toree passes the test, confirming their Middleton blood. The ceremony is interrupted by the arrival of the Empress Dowager, who summons Toree. The King, upon seeing Toree's reaction, decides to investigate Toree's parentage further.
Later, Toree is involved in another dramatic incident when John, Olivia's butler, takes Oliver hostage during dinner, driven by his unrequited love for Olivia and resentment towards those he believes caused her distress. Oliver, however, quickly subdues John. It is revealed that John had spread rumors about Toree, portraying them as a threat to the Middleton family. Olivia apologizes to Toree for the mistreatment.
The story concludes with Toree becoming closer to Brian and Oliver, who teach them various skills. They travel to the royal capital for the will ceremony, where Toree witnesses the popularity of the Middleton men. Paul is revealed to be Toree's biological father, though he is not a Middleton. The narrative then shifts to Toree's mother, Jade, who is not Toree's birth mother. The story culminates with Toree being formally recognized as a Middleton, with the King ordering an investigation into their true parentage.
