In a mansion where no detection magic can reach, the Demon King lives with his three daughters: the Succubus Princess, the Blood Demon Princess, and the Wolf Demon Princess. To help them grow up strong, the Demon King assigns them a human boy around their age as their "emergency rations." By day, he plays prey for the Wolf Demon Princess. At dinner, he serves as the Blood Demon Princess's "after-dinner dessert." Before bed, he provides the Succubus Princess with "nourishment." Julian, the three demon princesses' "emergency rations," spends his childhood with no room to breathe.
But just as the three princesses are about to come of age and leave Twilight Mansion, Julian accidentally overhears their conversation.
The Succubus Princess: "I'm going to 'drain' little Julian dry before the coming-of-age ceremony is over."
The Blood Demon Princess: "I have to be the first to 'eat' him."
The Wolf Demon Princess: "I'll definitely be the first to finish my 'hunt.'"
Faced with what seems like a hopeless, deadly end, Julian, who has been exploited by the three demon princesses for as long as he can remember, finally makes the bravest choice of his life.
"I'm going to survive!"
And so, determined to find a way to live in this desperate situation, the boy does everything he can to escape Twilight Mansion. Thus begins his uncertain fight for survival...
