Get back at the elves who look down on humans, take over the country, and become king! Take over the elven country and turn it into a female elf who will follow any lewd order without hesitation!

—To the elf king—

A world where various races exist "Eden". The races interacted with each other, but due to differences in appearance and abilities, they began to look down on each other, and at some point they began to repeatedly skirmish. Humans and elves, in particular, were often ridiculed together because of their similar appearance, and because of this, they were more conscious of each other than other races.

Before long, Elfen Lied, a large country ruled by elves and dark elves, declares war on Gravefield, a country of humans.

The main character, Gray (name can be changed), the leader of a mercenary group, participates in a war with the elves with his subordinates, but loses the battle and is taken prisoner. Their treatment was cruel, they were forced to do the harsh labor of mining in the mines during the day, and they were used as an elf's sexual release tool at night, and they were both physically and mentally tattered.

One day, Gray, who was involved in a mine collapse accident, accidentally learned the secret of Eden. And Gray, who obtained "power", started a rebellion against the elves with his companions.