Arc appears as a mysterious young man interacting with Yucie during her missions. He adopts a patronizing and teasing manner, frequently mocking her small size and commenting on her prominent forehead. Despite this rude behavior, Yucie feels drawn to him by an inexplicable sense of familiarity.

His true identity is Prince Arrow of the Human Realm. Years earlier, as a child, Prince Arrow found Yucie lost in a forest searching for sunset blossoms. He saved her from a wolf attack and helped her find the flowers, creating a lasting memory that fuels Yucie's admiration and her desire to grow up to properly thank him.

Operating as "Arc," Prince Arrow maintains an aloof facade, though glimpses of underlying concern for Yucie surface in his actions. This alias allows him to observe Yucie's growth and determination without the constraints of his royal status. Yucie's initial annoyance shifts towards romantic feelings as she recognizes his resemblance to her cherished memory of the prince.

During the battle against the ancient evil Diablo, Prince Arrow suffers critical wounds while aiding Yucie and her friends in defending the Fairy Realm. This injury becomes pivotal, directly influencing Yucie's ultimate choice regarding the Eternal Tiara's power. His recovery is secured solely through Yucie's selfless wish granted by the tiara, solidifying their bond.

Following these events, Prince Arrow continues to support Yucie as she and her friends return to their studies at the Princess Academy, now free from curses and able to mature normally. The relationship forged through shared trials and revelations remains central to his character arc.