Celli, originally named Serge Flora, is an enigmatic figure who wanders Europe as a photographer and collector of secrets. Shadowing the protagonist’s journey, he dispenses cryptic guidance and gifts symbolic flower seeds to those she aids—thistles for a farmer’s son embracing independence, for instance—each embodying lessons forged through their trials. His efforts conceal a twofold aim: to nurture others while quietly tending a hidden garden where blossoms infused with devotion converge, destined to birth the mythical Flower of Seven Colors.

Gradually unveiled as the Crown Prince of the Flower Star, a celestial kingdom ruled by plant spirits, Celli oversees the protagonist’s quest to secure the Flower, an emblem of his dynasty’s sovereignty. Though royal, he favors humility, stepping into conflicts to shield her from usurpers threatening his throne.

Their bond deepens from camaraderie to romance, yet when she declines his proposal to tend her grandparents, he forfeits his crown, passing it to his brother. Choosing Earth over dominion, he embraces a modest existence beside her, valuing connection above regal duty.

Beyond mentorship, he wields latent powers from his lineage, once reviving her with a royal crest-linked pin after a lethal crisis. His choices—guided by empathy and a resolve to harmonize two worlds—reveal an acute grasp of human fragility.

Marked by a feather-adorned hat, his design echoes his mystique. Though princely heritage drives the tale, his arc hinges on reconciling responsibility with heart, concluding not with crowns but quiet devotion to love’s enduring pull.