An immortal witch's grief spirals into chaos when she accidentally summons the Prince of Hell trying to stop her own tears. What unfolds is a comedy that treats emotional exhaustion like a legitimate disaster, the kind where a demon prince becomes your unwilling therapist because the alternative is listening to you cry forever. The show finds its rhythm in the specific absurdity of two beings who have nothing in common stuck in the same space, learning that sometimes the person who annoys you most is exactly the person who needs to hear you say it out loud.

Agate is a demon girl bound by a curse of eternal life. Having lost something precious, she cannot stop crying, and to leave her past behind she hurls half of her head into a deep valley and flees. Her tears pool into a lake at the valley's bottom and set off a flood in hell. Aloys, prince of the underworld, comes to the human world to find the cause and tracks her down, and a chaotic everyday life begins between them. Over 15 episodes, the ONA mixes comedy, fantasy and slice of life with a story of love.