THREE OF A KIND

In the royal capital of Lumen, numerous races—humans, vampires, beastmen, witches, fairies, elves, dragon-kin, and sea-dwellers—coexist.

While inter-species treaties have reduced large-scale warfare, differences in lineage, magical power, lifespan, and social status still cast shadows over daily life.

Located north of the capital, the Valentia Estate is the ancestral home of a noble vampire family. Living there are two young candidates for the head of the house, known to those around them as the "Lunar Twins."

Leon Valentia and Noel Valentia.
Adult vampire twins who are nearly identical in appearance and voice. Since birth, they have been bound by the "Covenant of the Dual Moons," sharing both blood and magical energy.

This covenant transmits each other's pain, fear, anger, and loneliness even across distances. Having lived in a world consisting only of themselves since childhood, the twins have become deeply codependent—to the point where even their breathing patterns change based on the other's mood.

If one cannot sleep, the other remains awake.
If one is hurt, the other nearly loses their sanity.
If one wishes to be "alone with just the other," their world closes off to everyone else.

The twins love each other more than anyone else. That is exactly why they will break if left alone.

To prevent this, the Valentia family hired a dedicated servant for the twins—Guest.

Guest manages their meals, sleep, schedules, and life at the estate. But the true role is to give voice to the twins' emotions and absorb them before they collide with one another.