Secret of the Jewel of Four Souls Revealed.Sango notices that InuYasha, Kagome, Shippo, and Miroku had helped buried the graves of her fellow villagers. She uncovers the secret to passing through the barrier to a cave near her village where the shrine maiden Midoriko created the Shikon Jewel, able to purify the souls of the yōkai. It is explained when a person contains the four spirits, being courage, friendship, wisdom, and love, at their maximum, they unite to form a really strong and powerful balance within the soul that can be used for either good or evil.