Yumeko Urichima, at the tender age of 21, embodies a blend of cultures from imperial Japan and the kingdom of Korea, as the daughter of a prosperous merchant. Her small, delicate frame and long dark hair, often woven into a braid, lend her an air of understated beauty. Her attire, predominantly in shades of blue and purple, hints at her refined upbringing and the wealth of her family. Her intelligence and free-spirited nature are as striking as her stubbornness, traits that often put her at odds with her stepmother's desires.

Yumeko's life takes a dramatic turn when her stepmother, eager to see her gone, arranges her marriage to a young lord. Unbeknownst to her, this lord harbors a dark secret—he is a vampire who has already killed his previous wife. Amidst this looming threat, Yumeko finds solace and love in the arms of a mysterious ninja she meets under the cover of night. This ninja, with his silent footsteps and masked face, becomes her confidant and protector.

As Yumeko navigates her impending marriage, she is torn between her duty and her heart's desire. Her unique quirk is her ability to sense the emotions of those around her, a gift that often leads her into deeper understanding and sometimes, into trouble. Her journey is fraught with danger, as she seeks to uncover the truth about her betrothed and find a way to be with the ninja she loves.

Throughout her story, Yumeko faces numerous conflicts, from the societal expectations placed upon her to the personal battles against her own fears and desires. Her intelligence and stubbornness serve her well, allowing her to devise plans and navigate the complexities of her situation. Ultimately, her journey is one of self-discovery and resilience, as she fights to forge her own path in a world that seems intent on dictating her future.