Tsukasa Tsukuyomi, later Tsukasa Yuzaki, possesses cascading pink hair fastened by a delicate clasp and eyes shifting from red to pink. She adorns elegant skirts and refined attire, reserving modern casualwear for home life, and dons a floral yukata during a Kyoto visit.

Once an ordinary apothecary, her existence transformed when the Hourai Elixir—administered by a servant to save the emperor’s daughter in a twist echoing *The Tale of the Bamboo Cutter*—granted her immortality.

Her life intertwines with Nasa Yuzaki after she rescues him from a truck accident. His immediate confession leads her to conditionally accept his feelings, demanding marriage—a vow fulfilled two years later when she hands him a marriage form, adopting his surname.

Serene and unshaken by Nasa’s impulsiveness, Tsukasa radiates kindness, aiding others with quiet grace. She revels in pop culture, voicing dismay when their home lacks a television, and shares vivid insights into Japanese history, swordsmanship, and landmarks, as though recounting personal memories.

Bound to lunar lore through her Tsukuyomi lineage, her grand-aunt Tokiko gifts her a moonstone to "ease her," anchoring her to celestial mythos. Tsukasa’s journey—marked by ethereal beauty, tranquil resolve, and timeless wisdom—shapes her bonds and choices, forever guided by the moon’s whisper.