Maburaho Season 1 Episode 13 He Came Back...

Starting with this episode, the focus of the girls shifts from trying to increase Kazuki's magic count to attempting to collect all of Kazuki's ashes in order to get his body back. Also, a mysterious girl meets Kazuki next to the maple tree. She asks Kazuki to point her in the direction to the old school building. Unfortunately, what Kazuki doesn't realize is that the mysterious girl wants to turn Kazuki into a complete ghost and add him to her collection of ghosts.