The Library of the Tortoise, located within Kyuden Kasuga, recorded the lineages and personal mon of the family. The Tortoise also secretly retained many of the original shameful truths that showed dishonor or disgrace in the Emperor's history, which were erased or never recounted in the official records, unknown even to the Shosuro-Ikoma Alliance. It was the only library which kept an eye on the lineage of the heimin.