Shaman King (2001)

Asakura Yoh is a shaman, a person who communicates with ghosts. He enters the Shaman Fight, for whoever wins the tournament gets to commune with the Great Spirit, God . . . that and his fiance Anna wants to be the wife of the Shaman King. Helping him are his friends Manta, Horo Horo, Ryu, and his samurai ghost partner, Amidamaru. Once every 500 years, there's an event called the Shaman Fight, and whoever wins becomes the Shaman King and can use the most powerful spirits ever. Asakura Yoh comes to Tokyo to train and become the Shaman King. Accompanied by many friends, he defeats many enemies along and the way, and gets more friends. Yoh is a young shaman, one who can see and communicate with spirits. Shaman's also have another power,the ability to unify with spirits and use the spirit's fighting skills. Yoh is training to become the Shaman King, strongest among all Shamans, a title won by winning the Grand Tournament that takes place every 500 years. Helping him are his best friend Morty, a short kid who can also see ghosts, Amidamaru, an old samurai and his spirit partner, and his fiance Ana, a spirit meduim and his trainer. However, another Shaman family is trying to keep Yoh out of the tournament. Along the way he meets a bunch of other misfit ghosts and wannabe Shamans.

Source: TMDb