"The last thing that remained was the promise with the dragon…"

In this continent where humans and demi-humans exist, it is in an era where both sides were clashing heavily…

In that kind of era, there was a man that had managed to make a variety of demi-humans coexist, and due to this, the human force ridiculed him by calling him Demon Lord.

The strong spirited king of Garuna, Verius.

He was one of the human kings that favoured the demi-humans.

And then, there's the family of Dragon Knights that served the king of Garuna -the Strauss. These foolhardy devilish swordsmen deftly drove flying dragons and protected the kingdom.

However, this kingdom that loves bravery would be falling as well…

Before the overwhelming numbers of the enemy, the father and brothers in the dragon knight family were killed.

The fourth son of the Strauss family, Solje, charged into the enemy lines together with the last remaining dragon of their family, Ares.

—Fighting in the battlefield and dying as a dragon knight, and then becoming a song, is an honor for them, but…Solje, who was supposed to have died in the battlefield, was brought back to life by the ancient dragon Ares with his mana.

The phantom of Ares speaks: "The Demon Lord has been killed due to the betrayal of our allied country".

"Kill these traitors", the ancient dragon Ares requests of Solje.

Hugging the bones of his beloved little sister, he pledges revenge.

Years passed after that…and his bitter enemy, the Faris Kingdom, continued increasing in power, and had become a giant empire.

With the cross of several battlefields, Solje was picked up by a mercenary called the White Lion.

The Banjar Mercenary Group; a mercenary group composed of a few demi-human elites fighting against the oppression of the Empire.

The Bow Princess Elf, the Giant Warrior, the Beastkin Girl, the Poet Man.

Having obtained reliable comrades, the fate of once again meeting a dragon began to move for Solje Strauss.

…This is the epic sung about the 13 war beasts and one black dragon