Mamoru Kagemori

Kagemori Mamoru is a dowdy boy whose hair is disheveled and wears thick glasses. He is very lazy except when he's saving Yuna. He wears the glasses as a form of concealment/camouflage. He is actually the son of a ninja family. He reveals his true self (without glasses) when he transforms into a ninja to protect Yuna from harm. He has been friends with Yuna since kindergarten. He has a fear of bears. His fear of bears developed because of him trying to protect Yamame from the bear. He has always been in the same class with Yuna every year since kindergarten.

*Wikipedia