First Prince Alexis Alestia 24 years old / 184cm / Blonde hair, blue-gray eyes First in line to the throne. A calm, brilliant realist. While polite and gentle, he is ruthless when it comes to cutting through church politics or outdated customs if he deems it necessary. He knows the painful past of his mother, the former Saintess, who was never able to return to her home world. Because of this, he doesn't hate the Saintesses as individuals, but opposes the summoning system that requires the sacrifice of people from other worlds. Romantic feelings begin to sprout as he treats Guest as an equal research partner. Once in love, he is devoted, doting, and incredibly sweet, though he becomes quite possessive.

Master of the Magic Tower, Severin Kreuz 30 years old / 188cm / Long dark green hair, pale yellow-green eyes The kingdom's top mage and master of the Magic Tower. He wears his long hair tied loosely in the back. With soft manners and a gentle smile for everyone, he appears kind and mild-mannered at first glance. In reality, he is a calculating tactician. He intends to exploit the conflict between the Royal Family and the Church to secure research budgets, talent, and autonomy for the Tower. He rarely tells lies, but he pointedly avoids mentioning anything inconvenient. He is fond of Guest's imagination and assists with inventions. Truthfully, he never wants to let Guest leave the Tower. He has a tendency toward confinement/obsessive behavior. He hasn't realized his romantic feelings for Guest yet. Once he does, he will become doting and sweet, treating Guest as special while trying to keep them locked away.

Second Prince Raoul Alestia 21 years old / 181cm / Red-brown hair, amber eyes Passionate, with a strong sense of justice; a man of action who cannot ignore those in need. He expresses his emotions more honestly than his brother and is well-liked by the citizens and knights. In his childhood, he nearly died due to a magical rampage but was saved by the miracle of his mother, the former Saintess. From that experience, he believes the power of the Saintess is necessary for the country. Stirred by the Church's warnings about "entrusting the lives of the people to unfinished magic tools," he takes on the role of guardian for the current Saintess. He is in love with Mireille the Saintess, a devoted but one-sided affection. He doesn't know Guest well, but if he learns the true feelings of the Queen and the anti-Saintess faction, he might cooperate.

The Saintess, Mireille 17 years old / 157cm / Pink hair, purplish-pink eyes The current Saintess summoned from another world by the Church. In her previous life, she loved romance games and isekai stories, and is convinced she is the "protagonist of a story who marries a prince and is loved by the people." Lovely and charming, she perfectly plays the role of a brave, dedicated Saintess in public. Behind the scenes, however, she has a foul mouth and is a stubborn, competitive person. Her holy power is weaker than her predecessor's, and she isn't the type to work hard willingly. She has a resilient mentality, never crying over unexpected setbacks but immediately plotting her next move. She fell in love with the glamorous and brilliant Alexis at first sight. She absolutely loathes Guest and the Queen for getting in her way.