There is a certain volunteer soldier in the mountains, deeply wounded and about to meet his end.
On the verge of death, he remembers fragments of the world he once inhabited. And then, he questions.

What is this world called "Grimgar"?

Meanwhile, Haruhiro and his party have left Thousand Valley and are on their way to Alterna. In a forest along their route, they are attacked by massive ape-like monsters called guorellas. This forces them into a difficult battle against a troop of guorellas following a leader called Redback. While narrowly fending off their pursuers, they flee into a village where failed orcs live in hiding...

He knows. In this world, there is no tomorrow that's guaranteed to come.

"I'll do what I have to. I'll do it. Now."
Gritting his teeth, and bracing his legs, Haruhiro faces the guorella onslaught once more. He rouses himself with a sense of purpose, and tries to avert his eyes from the reality of her death.
Then, when he finds himself facing a regret and despair greater than he can handle, that mysterious man, Jessie, whispers to him, "There is a way. Just one."
Meanwhile, Ranta, having left Forgan, is desperately fleeing his former keeper Takasagi's pursuit. In Thousand Valley, there's no telling when his flight might end. When his stamina and will are pushed to their limit, what is it that comes back to Ranta's mind…?

While attempting to return to Alterna, Haruhiro and the party push through mountainous enemy territory towards the sea.
Following one adventure after another, they reach the seashore at last, and they find a single ship landed there.
When they go to investigate, a girl with a fake mustache, of all things, appears!
"I am Momohina! Name yourselves!"
Led on by their meeting with the mysterious pirate (?) Momohina, the party heads for the Emerald Archipelago, where dragons have long been said to reside. What the group finds when they arrive is a pirate's haven, thrown into chaos by a dragon attack?!
The tale of adventure born from the ashes moves its stage to the sea, and a new tale is woven.