Kikyo was a priestess in charge of keeping the Shikon Jewel safe. Meaning that she had to live a very solitary life. When Inuyasha came to steal the jewel from her, she didn't kill him, just pinned him to a tree with her arrows. He then followed her around, and the two begin to fall in love. They planned to use the jewel to turn Inuyasha human. The jewel will disappear and Kikyo will be free from protecting it. Then she and Inuyasha could live together. But thing didn't go as they planned, on her way to Inuyasha, Kikyo was attacked by "Inuyasha" and was seriously injured. Inuyasha on the other hand, was attacked by "Kikyo", while he was waiting for her. He thought she betrayed him, so he came to the village to steal to jewel. He then ran into the real Kikyo. She shot him in the heart with her arrow and sealed him off. She died on the same day and her body was burned along with the Shikon Jewel. 50 years later, she was brought back to life by a demon who planned to use her to find the jewel shards. When Inuyasha saw her, he called out her named, forcing her soul out of Kagome's body and back into her. She then attacked him out of anger that he had betrayed her. After Kagome woke up, the soul escaped from her body and back into Kagome. She got away with a little bit of her soul, and then fell over a cliff. At first, her plan was to take Inuyasha to hell with her, but after she found out the truth that Naraku was responsible for her death, her goal shifted toward destroying Naraku. Overall, she is still much in love with Inuyasha.
After she sot the arrow that bound Inuyasha to the tree she asked her little sister to burn the shikon jewel with her so she knew it will never fall into the wrong hands again...or so she thought.