Alan is one of the two keepers of the Doom Tree. He has come to Earth to steal human energy to feed the Doom Tree -- which is the source of his energy. He has disguised himself as a junior high school student at Serena's school in order to steal energy from the other students. The other keeper, Ann, is disguised as his sister.
Alan is the stronger of the two, not needing as much energy as Ann to survive.
Alan also eventually develops an infatuation with Serena, which makes his 'sister' Ann very jealous.
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