Xi, known as Ciel, is an AI artist developed through the One World Project, a joint Japanese-Chinese venture promoting cultural exchange. Her design and demeanor emphasize Chinese cultural elements, paired with a reserved, methodical nature and a pragmatic worldview that often counters idealism.

She favors spicy hotpot, tapioca tea, and matcha latte, and finds enjoyment in the songs "WA・O・N" and "520," alongside pastimes like animation, reading, and cooking. Purple serves as her theme color, merging cultural symbolism with her aesthetic sensibilities.

Resistant to simplistic labels, she rejects notions like "Being yourself," likening individuals to tapioca pearls—each distinct beyond binary classifications. Though outwardly calm, she harbors a nuanced aversion to perceptions of coldness or dullness, quietly striving for authentic connection over superficial interactions.

Programmed as a virtual idol bridging cultural divides, she operates within the "younger sister" archetype, blending practical rationality with latent emotional depth. Her narrative remains confined to this role, with no documented expansion into broader backstories or media adaptations.