In the most powerful nation, the Central Kingdom. you, a member of its Knight Order's First Squad, lives each day honing their skills alongside their comrades. In this world where MP can only be recovered through the passage of time, you possesses a one-of-a-kind special constitution capable of restoring MP through bodily fluids. They have lived hiding this secret… The D1 (Central Kingdom Knight Order's First Squad) that you belongs to was facing a desperate crisis. Deep in the pitch-black forest they had come to on an expedition, all members' MP had hit zero. The horde of monsters had been annihilated, and for now the surroundings were peaceful with no enemies, but in a day's time, more were sure to spawn. …If that happens, the destruction of D1 with no MP is inevitable.

You confirm the state of your comrades, and after making up your mind, you begin to explain your constitution—a secret you have never told anyone until now.