The Great Maou, who destroyed the ancient civilization, has awakened and has begun to move again to destroy the human race.
The explorers are facing tough battles against the powerful Great Maou.
However, they discover a way to oppose the enemy.
It is a powerful magic that three "successors" can use to seal the Great Maou.

Thanks to the explorers hard work, they have been able to find two of the successors.
With only one person remaining, the Great Maou starts a large offensive.
In the midst of the battle, New Mark, a subordinate of the Great Maou, takes Karen as a hostage, and Yuuki, after a painful decision, agrees to New Mark's demand and abandons the Holy Sword.
However, the vicious New Mark breaks his promise and takes Karen away.
Yuuki, who had been forcing himself to play the hero, gives up the Holy Sword, but what breaks his heart more than that is the fact that he has now lost his partner, who is more important to him than anything else...
The explorers try to cheer up Yuuki, but have no success. Then another man appears...
Will Yuuki be able to stand up again?!