Long ago a type of mushi called The Forbidden Mushi was sealed away in a member of the Karibusa Family as a result that person developed a coal like mark on her body. Since then every now and then someone with a coal like birthmark is born. This person is called a Scribe.
The part of the body with the mark has the Mushi sealed in it. The Scribe's duty is to record every detail related to mushi, these mainly include stories from other Mushi Masters. By doing this the Forbidden Mushi inside the Scribe gets sealed away within the texts of scroll. The sealing process gives great pain to the Scribe as the portion where the coal like mark is put immense pain on the scribe. As the mushi gets sealed away the mark reduces little by little. But till date no Scribe has managed to completely get rid of the mark.
If a scribe manages to seal all the mushi inside them away then the further generations won't be affected by the mark.
The scroll itself is stored within the Archives, since with the passage of time the paper gets old the text in the scrolls must be copied into new scrolls to avoid the mushi to escape.