Guardian Ninja Mamoru(陰からマモル！)

Kage Kara Mamoru! is a series of light novels written by Achi Taro. The light novels had ended in March 2008 with the release of Volume 12, but as of July 2009, a new series entitled Motto! Kage Kara Mamoru! has started serialization. It features manga and anime adaptations. The main character is Mamoru Kagemori, a ninja who is sworn to protect his neighbor Yūna Konnyaku.