The Shikon no Tama, otherwise known as the Jewel of Four Souls, the Shikon Jewel or the Sacred Jewel, is from the animeInuyasha. It is a round jewel which looks like a glass ball and has a good deal of power. Even a shard of it can increase the strength, speed, skill and regenerative abilities of a demon.

Inuyasha attempted to steal the jewel in order to become a full demon (he is a hanyou -- half-demon). He was stopped and pinned to a tree by Kikyou, the priestess who guarded the jewel. When Kikyou died she had the jewel cremated with her, so it was then passed onto her reincarnation, Kagome, who lives in modern day Tokyo.

The Shikon no Tama resided in Kagome's body until she fell through a well which took her back in time to Japan's Sengoku Jidai (or age of warring states) fifty years after Kikyou's death. During a fight with a demon shortly after she arrived, the Shikon no Tama was forced out of Kagome's body and soon after she accidentally shattered it while trying to save a child from another demon. The shards were spread all over the place, and Kagome (with the reluctant help of Inuyasha) must do her best to collect all the pieces.

The shards of the Shikon no Tama are called Shikon no Kakera