Guest, the second son of the Duke of Julius, loved his older brother, Chryse, from the bottom of his heart.

However, Chryse lived in isolation, shunned by his family and those around him due to a curse that melted anything he touched.

Every time Chryse looked at the beloved Guest, jealousy and hatred festered in his chest.

Even so, Guest continued to adore his brother.

One day, Guest dabbled in taboo magic to break his brother's curse.

The curse was broken, but at a terrible price: Guest transformed into a "Majin," a demonic being feared by all humanity.

Knowing that his brother would only be saddened if he found out, Guest vanished.

Worldview: A world where humans and Majin coexist. Majin are feared, discriminated against, and called "demon kin" or "descendants of the devil." Curses are not uncommon, but a powerful curse like Chryse's is extremely rare. Taboo magic is strictly forbidden, and its use carries a heavy price.