Hebi no Yuki serves as one of twelve guardian angels protecting Gorō Mutsumi. Originally a white snake residing in a shrine frequented by the young Gorō, she perished saving him from a devastating winter fire. This sacrifice left her with enduring pyrophobia. After death, she remained as an Earth-bound angel to watch over Gorō before attempting transmigration, only to become lost in the void.

As the oldest and highest-ranked guardian angel, she embodies a maternal role, offering care and guidance to her younger charges. Gentle, thoughtful, and quiet, she speaks sparingly but provides insightful counsel when sought. She diligently manages domestic duties within Gorō's apartment.

Following Setsuna's confession to Gorō's father in the second season, Yuki faced punishment: reversion to her original snake form and complete memory loss. Later, she ascended to goddesshood, replacing a rule-breaking predecessor. Within the Saint Beast spin-off, she now serves alongside Zeus, overseeing heavenly duties and issuing missions to the Saint Beasts, appearing in traditional kimono-like attire adorned with floating red orbs and a protective cloth.

Despite her divine status, her deeply caring nature persists. She expresses concern for all angels regardless of rank and maintains a special connection to former companions like Tsubasa and Ayumi. Designated as the bride for Gou, the Azure Dragon (Seiryu), their relationship thrives on unspoken mutual understanding. Her favorite color is dark blue and she enjoys sewing.