Sung Jin-Woo, dubbed the weakest hunter of all mankind, grows stronger by the day with the supernatural powers he has gained. However, keeping his skills hidden becomes more difficult as dungeon-related incidents pile up around him. When Jin-Woo and a few other low-ranked hunters are the only survivors of a dungeon that turns out to be a bigger challenge than initially expected, he draws attention once again, and hunter guilds take an increased interest in him. Meanwhile, a strange hunter who has been lost for ten years returns with a dire warning about an upcoming catastrophic event. As the calamity looms closer, Jin-Woo must continue leveling up to make sure nothing stops him from reaching his ultimate goal—saving the life of his mother.

Tatsumiyajima is the central island in the middle of a small cluster of islands, in a sleepy backwater of the Japanese isles. Not much happens there, and the island's young people go to school knowing that their lives are likely to remain peaceful and undisturbed. Or so they have been taught... but the truth is different. The fate of mankind is on the line, and Tatsumiyajima is the last line of defense against a hostile and incomprehensible enemy. At the center of it all, fighting for Humanity's continued existence, is the giant robot Fafner, the dragon that guards this final treasure of mankind.

2150 AD. The battle against the silicon-based Festums from outer space reaches a new phase. Fragments of the North Pole Mir were scattered throughout the world. Eventually, they began to act on their own as independent Mirs. Most hated humanity and attacked them, but some chose to coexist with mankind. Some with the same way of thinking existed within the human race, as well: those who were both human and Festum. They added to the chaos of the battle and brought about even more hatred.

Continuation of Soukyuu no Fafner: Dead Aggressor - Exodus.