The guardian of the Shikon no Tama was a role performed by the miko Kikyō shortly before her death. A group of demon slayers found the Shikon no Tama inside the body of Mistress Centipede and entrusted it to Kikyō to purify and protect from falling into wicked hands. The role was coveted by the dark priestess Tsubaki, who tried to kill Kikyō to gain possession of the Jewel, but was maimed by her own attack during the attempt. Kikyō was a target for many demons who, like Tsubaki, coveted the Jewel and eventually she fell victim to a plot by Naraku, whose very existence was perpetrated by a lust for the Sacred Jewel.
When Kikyō died, she ordered that the Jewel be burned with her body and it disappeared for fifty years, and there was a period of peace. However, the Jewel later returned inside the body of Kikyō's reincarnation, Kagome Higurashi, who traveled back in time to the feudal era through the use of the Bone-Eater's Well. Shortly thereafter, the Jewel became fragmented, and Kagome undertook the task of collecting the scattered Jewel shards and purifying the completed Jewel. However, after Kikyō was resurrected, the reborn priestess still considered it her duty to purify the Jewel and use it to destroy Naraku, leading to some conflict with Kagome and her friends. After Kagome wished for the Jewel to vanish, there was obviously no need to protect it anymore and she was able to live in peace with Inuyasha.