'Spark is actually the archive of the former Sesshoumaru/Kagome website "A Single Spark," which was owned by the marvelous ~Winter~. She hit a wall with moderating and dealing with that site so, when our own Miss Kagura opened Dokuga, ~Winter~ offered to let us host the stories on "A Single Spark" when ~Winter~ shut down the site. It was the perfect way to save all the wonderful stories people loved that were on the 'Spark site and, at the time, it more than doubled the stories we were hosting here.
In deference to both the authors of the stories on the 'Spark archive, as well as to ~Winter~, Miss Kagura made the 'Spark archive a stand-alone archive that was linked to Dokuga, but not a part of it. It was a way to make sure people knew that those stories & other works on the 'Spark archive were uploaded when "A Single Spark" was an active site. For that reason, everything is searchable only on the 'Spark tab, and it is distinct and separate from Dokuga proper.
I hope that helps answer your question. Please don't hesitate to holler if you have any other questions!!
~~WiccanMethuselah~~
Site Administrator