Aku no Musume

The Kingdom of Lucifenia, widely known as the "Kingdom of Yellow," is ruled by the iron fist of Riliane, a fourteen-year-old princess whose absolute authority knows no bounds. Under her tyrannical reign, the populace is ruthlessly exploited, and anyone who dares to defy her will faces swift and merciless execution. The people have come to call their young ruler the "Daughter of Evil." Yet, standing faithfully at her side through every cruel decree is Allen, a servant who bears a striking resemblance to the princess herself. Though they appear to be nothing more than royal and retainer, Riliane and Allen share a hidden past: they are twins, separated shortly after birth. While Riliane ascended to the throne in her mother's place, Allen was given up for adoption and eventually brought into the palace to serve in obscurity. Bound by this secret, he remains her constant shadow. However, the princess’s unchecked selfishness and consuming jealousy soon ignite a devastating war, leaving countless lives lost in her wake. As tragedy unfolds across the kingdom, the hidden clockwork of fate binding the two siblings begins to spin wildly out of control.