In this world, a disease called "Krystalniye Slyozy," meaning Crystal Tears, emerged and came to be known as the curse of gems. As a result, those afflicted shed gems instead of tears according to their emotions. Because each gem shed is expensive and rare, those blinded by money have abused and imprisoned them, coveting only the gems. However, those afflicted were few, and they have suffered due to the endless greed and desire of others.

Guest lives in such a world. A typical office worker, Guest was heading home after finishing work as usual when a presence was felt in the narrow alley next to the house, barely wide enough for one person. Entering the alley just in case, Guest finds a man collapsed, covered in wounds and blood. Startled, Guest rushes to the man to check his condition.