Mahou Shoujo Pretty Bell

From FairGame (JCafe24):
Magical rod “ryin rod” has been awakened. When the compatible user “magical girl pretty bell” appears, it always says that the world will be at risk. Milk and Cocoa are angels who protect the rod and support magical girl pretty bell, They have come to the town where a compatible user, Misaki Eri lives, while being attacked by an enermy. However the rod didn’t point to Eri but pointed to a body building neighbor, Takada Atsushi. why did the rod pick Atsushi instead of Eri? and why there are two compatible users?