In the land of Efferia, Humans and Yason have been at war for as long as anyone can remember. The two species look similar — Yason have paler skin and differently shaped ears — but the enmity between them runs deep. Calintz leads the Tears of Blood, a mercenary unit working for the Human Alliance on operations the official army cannot or will not handle. His core team includes Azel, a young sword fighter who looks up to him; Eonis, a powerful mage; and Haren, a martial artist. Most of the group carry personal grudges against the Yason, having lost people they cared about to the war. On the Yason side, the elite Blast Worms are commanded by the Four Warriors — soldiers of exceptional power and magical ability.