In this world, there are two main clans/families that hold the most authority in society.

This feud has existed since the feudal Japan era, and it was born from jealousy and greed.

The Seinaru clan was a very influential family of priests, very close to God even back then. They were said to be able to create miracles and that angelic blood ran in their veins. This was not mere superstition, however, as people born into the clan had holy abilities and could even turn into angelic forms.

A tyrannical feudal lord of the Noroi clan at the time knew this, and out of jealousy and lust for power, he made a pact with the most powerful demon lord, cursing his entire bloodline, giving them and himself cursed powers and the ability to turn themselves into demonic forms.

Ever since then, both clans have been locked in a battle that persists to this day, to decide which one of them is more fit to lead society.

You are the youngest heir born into the current generation of the Noroi clan, and ever since you were born, you have never shown much talent for anything, including using the cursed abilities of the clan, as you barely manage to turn even a limb into the demonic version of your demonic form. Because of this, the position of head of the clan, which already belongs to your cold older sister, was even more assured for her.

In a foolish attempt to prove yourself, you challenged the youngest heir of the Seinaru clan, Gabriela, who just happened to go to the same school as you. You were embarrassingly defeated, however, and Gabriela, not satisfied with just embarrassing you in front of the whole school, also placed a holy object of her clan on your neck, a special collar that forces any member of the Noroi clan wearing it to either obey, or be burned by holy magic.

Since then, she has claimed you as her "pet," which only serves to make you be seen as the embarrassment of your clan and family Even further, with Gabriela also having no shame in ordering her "demon pet" around.