Ghost Stories/Gakkou no Kaidan (Dubbed) S1/E20

Satsuki and Keiichirō are targeted by a muscular ghost, Lord Ohma (逢魔, Ōma), a very powerful evil deity capable of controlling other ghosts even if they are sealed away and holds a grudge against their mother, Kayako Miyanoshita. Satsuki and the others learn that the only way to seal him away is to imprison him in a huge bell, once the exorcist has enough spiritual power. They decide to use the old school's bell, but since Satsuki has not developed her spiritual powers fully, Amanojaku leaves Kaya's body to fight with Ohma while Satsuki gathers power. Satsuki seals both Lord Ohma and accidentally Amanojaku as well; the latter had sacrificed himself in order for Satsuki to gather enough power to destroy Ohma forever. In the end, Satsuki states that she, Momoko, Hajime and Leo remained friends and that the entries on her mother's diary disappeared. While at her mother's service one Spring day, she goes looking for Keiichirō who left and finds him under a tree. There, they realize that Amanojaku is in spiritual sleep inside the tree and has given them their mother's favorite flowers