At ten years old, Pia Rockwell, the daughter of a count, recovers her memories of a past life as a Japanese doctoral student specializing in paleontology. Along with these memories, she realizes she has been reincarnated as a minor villainess in an otome game called Caroline and the Rainbow Magic Sweets. Knowing that in the game’s storyline she is fated to be publicly banished by her fiancé, Rufus Stan, for a petty act of jealousy, the timid Pia becomes determined to avoid this future. Her dream is not to engage in noble politics or romantic intrigue but to become a paleontologist, excavate fossils, and live peacefully as a commoner curator.

Hoping to change her destiny, the fearful Pia musters her courage and asks Rufus, the brilliant and calculating son of the prime minister, to break off their engagement. Instead of agreeing, Rufus forces her to confess everything she knows about the game’s plot. Rather than being angered by her prediction that he will fall in love with the game’s heroine, he is intrigued and makes a counter-offer. He proposes a bet: if he ever falls in love with Caroline, the heroine, he will give Pia a vast sum of money and territory in seven years. Unable to refuse his imposing demeanor, the extremely timid Pia accepts, binding their fates together.

However, Rufus has no intention of letting Pia go. He has secretly fallen in love with her, misinterpreting her constant fear of being abandoned as a fear of losing him, which he finds endearing. He also values her genuine, unfashionable passion for fossils and her complete lack of interest in his status or wealth. Unbeknownst to Pia, Rufus begins a campaign of proactive protection and subtle manipulation, using his political acumen to neutralize any potential threats to her before they can even arise. He works to solidify her position and surround her with allies, ensuring that the game’s original plot cannot come to pass.

The story follows Pia’s daily life as she navigates high society and later the royal academy, all while Rufus’s overbearing yet devoted love closes in on her from every angle. Key narrative arcs include Pia’s childhood friendship with the game’s heroine, which becomes complicated; her struggles to establish a museum and pursue her paleontological research; the introduction of other reincarnated individuals; and the lingering mystery of the magical sweets that originally triggered the game’s conflict. Despite the looming threat of the game’s scenario and Pia’s own overwhelming timidity, the narrative focuses on her slow acceptance of her new reality and the powerful, unwavering protection of her cunning fiancé.