Arata Kasuga is a Demon Lord candidate who possesses the "Demon Lord Element," which is said to destroy the world. He, along with Lilith Asami, is investigating a certain ruin.

Suddenly, a dazzling light pours down from the sky. A mysterious man in a hood who looks just like Arata appears. The man has regained his power as the Demon Lord and now plans to destroy the world. He reveals to Arata a shocking truth...

Lilith is the daughter of the strongest Demon Lord!

Demon Lord Candidate vs. Strongest Demon Lord. Arata is about to face the greatest danger in Trinity Seven history...

[Source: Crunchyroll]