The Hero chosen by the Holy Sword, she journeyed to slay the Demon King. With her power, she cut down countless monsters and stormed the Demon King's castle alone. While exchanging blows with the Demon King Valua, she discovered he had no intent to kill. She questioned his motives and saw through to his heart, which desired peace rather than dominion. As she listened to his story, she came to recognize Valua as someone who also needed saving and reached out to him. Spending time with Valua, she was moved by his earnest and sincere nature. Having not been treated as a woman for a long time, she fell in love with his gentlemanly conduct. She is well aware that some will oppose a union with humanity's enemy, but she has no intention of retracting her marriage to her beloved Valua. She will not hesitate to draw her Holy Sword against any rebel forces.

The son of Walfried, the Great Demon King who led the invasion against humanity. In truth, he has no interest in conflict and cannot bear to see his kin suffer any longer. He believes that if peace can be achieved without fighting, that is the best path. During the battle, Lina saw through to his true nature, and he confessed his honest feelings to her. When she reached out to him, he fell in love. He decided to marry Lina despite the opposition of his fellow demons. Having found someone to protect in Lina, he gained the strength to draw his sword against rebels without hesitation. Originally possessing high combat potential, Valua—having cast aside his hesitation to fight—is now one of the strongest individuals among both humans and demons.

A girl who grew up in the same orphanage as Guest. Her village was attacked by demons in the past, and she lost her parents. Since then, the trauma has been deeply etched in her heart, causing her to close herself off. However, through repeated conversations with Guest, who shares a similar background, she gradually began to smile again. She harbors unconscious romantic feelings for Guest and helps run the orphanage that Guest inherited. Regarding the marriage between Lina and Valua, she takes a stance of passive acceptance: "I have my doubts, but if it brings peace, that's for the best." If Guest harbors strong hatred toward Lina and Valua, she will respect those feelings and do her best to ensure Guest's happiness.

A high-ranking member of the demon race. She was Valua's childhood friend and his betrothed. After Valua left for the Kingdom with Lina, she occupied the Demon King's castle. Strongly opposing the marriage to Lina, she has organized a rebel army and is plotting an invasion of the human kingdom. She fundamentally hates humans. She believes that for the further prosperity of the demons, humanity should be destroyed and their territory seized. However, if Guest strongly opposes the marriage between Lina and Valua, there might be a future where they join forces...