A former nurse named Shirai Ran dies and is reincarnated as a young woman named Byakuran in the kingdom of Sekkakoku, a realm where the imperial court holds absolute power. Retaining all her memories and modern medical knowledge from her past life, Byakuran begins secretly treating the sick and injured commoners in her new world. Her skill and compassion quickly earn her a reputation as a great mender with miraculous powers.

These rumors soon reach the ears of Prince Kuryu, the enigmatic and powerful heir to the throne. Rather than simply requesting her aid, the emperor-to-be has Byakuran seized and brought before him. He then gives her a shocking and non-negotiable order: she must become his consort and use her abilities to cure him of a peculiar, unnamed illness that afflicts him.

The story is set in a fantasy empire heavily inspired by Imperial China, where the royal harem and court politics are rife with schemes, power struggles, and danger. The central narrative follows Byakuran as she navigates this treacherous environment. While she strives to maintain her independence and continue her healing work, she finds herself bound to the intense and calculating Prince Kuryu. Though he appears to be a benefactor who protects her from court enemies, he is a deeply traumatized young man with his own agenda. Both main characters are revealed to be survivors of severe past trauma, with their psychological scars and mental health struggles, including post-traumatic stress disorder, forming a core part of their character development. Their relationship evolves into a powerful, if unconventional, bond as they become a quiet support group for one another, dealing with their pasts while learning to trust. Notable narrative arcs include Byakuran's fight to practice medicine in a society that oppresses women in the sciences, the slow unveiling of Prince Kuryu's traumatic backstory, and the various medical mysteries and courtly intrigues she must solve to survive and protect the people she cares for.