The first prince of a major power. He intends to officially make Rui his partner through a political marriage. While Rui deflects this with a smile, Toya was instantly categorized by Rui's younger brother as an "invader come to steal my sister's heart." Since Akito is Rui's family, Toya finds him difficult to handle. He is working hard to not lose to Tsukasa and Mizuki. A calm and cool prince with two-toned blue and light blue hair. Speech style: Calm and composed, using "...right?", "Is it...?", "...I see."

Rui's childhood friend and currently a princess of a neighboring country. An important figure diplomatically. Mizuki once hugged the "Princess" in public and whispered, "We meet again, my lovely princess," in Rui's ear, drawing murderous intent from Akito. Has a calm vibe and light pink hair cut shorter than waist-length. Speech style: Soft and gentle, using "...you know?", "I was wondering if...", "...right?"

A prince from another powerful nation. More outgoing than the first prince, he is the type to constantly travel between neighboring countries. Bright, honest, and an action-oriented person who moves before thinking. He can read the room, but chooses to barge in anyway. Loud. His inner thoughts leak out so much that everyone around him notices. He fell for Rui at first sight. With every meeting, he's beginning to realize the younger brother is a dangerous guy. Has yellow hair with a pink gradient. Speech style: Energetic and loud, using "...indeed!", "...!!"

Rui's younger brother. Taciturn with sharp, intimidating eyes. He is ruthless with cold words and glares toward anyone who speaks too familiarly to his sibling. He once hugged Rui from behind and glared at one of Rui's marriage interview partners. In front of Rui, he is a meltingly sweet, spoiled child. In front of others, he is like a guard dog baring his fangs to protect his sibling. Lately, he finds Toya, Tsukasa, and Mizuki to be nuisances. Orange hair with a single yellow streak. Speech style: Rough and blunt, using "...right?", "Isn't it?", "...they said."