Leon Fou Bartfort is the central protagonist of the story. In his previous life, he was a Japanese office worker who was forced by his sister to play a difficult otome game. After dying from exhaustion, he reincarnated into that very game world as a minor noble from a baronial family. Upon regaining his memories at age five, he realized he had become a low-ranking mob character in a matriarchal society where men are treated as second-class citizens.

Leon takes a pragmatic and realistic outlook on life. He does not care for appearances or playing by the rules, and he is quick to call out others for their hypocrisy, cowardice, and condescending attitudes. Despite his cynical and often rude exterior, he consistently intervenes to protect the game's original heroines from ruin. He enjoys showing arrogance in his abilities as a tactic to damage an opponent's confidence. His primary motivation is to live a quiet, comfortable life in the countryside, but the political instability of the Holfort Kingdom forces him into the spotlight.

Using his encyclopedic knowledge of the game's mechanics and hidden items, Leon secures an advanced ancient AI ship named Luxion. This AI provides him with superior technology, tactical support, and sarcastic commentary. Leon is a capable pilot and strategist, and he wields a sword in battle. His combat style relies on intelligence and strategy rather than brute strength. He also pilots advanced battle gear and airships that far outclass standard equipment.

Leon's role in the story evolves from a self-serving mob character looking to avoid trouble into a reluctant hero and high-ranking noble. He navigates the dating sim tropes he despises, and through his actions he reshapes the kingdom's political landscape. He eventually rises to become king and establishes the Bartfort Dynasty.

Key relationships include a protective bond with Olivia, the original game protagonist who possesses light magic, and Angelica Rapha Redgrave, the former villainess whom Leon defends in a duel. He becomes engaged to both of them in a polyamorous arrangement. He shares a bickering, antagonistic relationship with Marie Fou Lafan, who was his sister in their previous life and now usurps the heroine's role. He also develops a respectful rapport with Queen Mylene, who recognizes his competence, and he defeats Hertrude Sera Fanoss, a vengeful enemy leader, choosing to spare her life and earning her respect.

Leon's development is marked by a transition from a purely self-interested survivor to a leader burdened by responsibility. Despite his constant desire for obscurity, his competence and the necessities of his situation force him into positions of immense power, ultimately changing the world around him.