The beings known as Crimson Denizens and Rinne, who come from a different world, have developed a taste for devouring precious human existences. The task of maintaining balance in the world and subduing these dangerous creatures falls upon the Flame Hazes. Unaware of these events, Yuuji Sakai begins his day like any other - heading off to school. However, everything changes when he witnesses his peers frozen in place and realizes that he is the only one capable of moving. In an instant, a Rinne appears and begins consuming the souls of those around him. Thankfully, a Flame Haze with fiery red hair and a katana comes to his rescue. After the chaos caused by the Rinne is resolved, the Flame Haze informs Yuuji that he is now a Torch, a fragment of a deceased human's memory that will eventually fade away. However, he is also a Mystes, possessing a mysterious treasure within his Torch status. Before his flame is extinguished, a Crimson Denizen will attempt to claim this treasure, so the Flame Haze vows to protect him. Although it's difficult to come to terms with his impending death, Yuuji chooses to cherish the remainder of his precious existence.