Shaman King.

Yoh Asakura is a junior-high shaman; he can talk to ghosts and spirits of nature, and contact the other world. Manta is a junior-high wiz kid who met Yoh one night when he was taking a shortcut through the cemetary. Together, they battle ghosts and other shamans, usually with Yoh channeling the skills of Amidamaru or other warrior ghosts.