"There are countless fissures in the physical world. Those who vanish like smoke are lost in such hollows. Without their memories, without their souls..."

Ginko receives a letter in a cocoon, but it isn't adressed to him. Rather, it's addressed to an old accquaintance, Aya Tozawa, so he decides to visit her. Ginko is concerned about Aya, as she is still searching for her sister, who has been trapped in an Uroana for 5 years.

Ginko arrives at a secluded place, to meet an old acquaintance, who seems to be in charge of a large volume of archival, confidential text. Ginko is allowed to read it, and discovers it is the work of Tan'yu, a writer. Tan'yu is the descendant of the Karibusa family, being born with a black mark on a part of their body.