is a Japanese 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 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. Story The Kagemori family has secretly protected its neighbor, the Konnyaku family, for 400 years. Mamoru has been the protector of the daughter, Yūna Konnyaku, since they were in kindergarten. When Yūna is in trouble, Mamoru quickly puts on his ninja suit and transforms into a competent ninja; able to protect her from harm. Unfortunately, this poses quite a challenge as Yūna, being both clumsy and absent-minded, often stumbles into situations where Mamoru must once again come to her rescue. On the first day of their new school term, a model airplane accidentally makes a dive towards Yuna, but it is quickly stopped by a thrown kunai. At school, Airi Sawagashi invites Yūna to go bowling, but is unhappy when Mamoru also comes. At the bowling alley, Yūna wanders into the men's restroom and interrupts a yakuza deal involving fake dolls. As a result, they kidnap her and take her to their boss. Mamoru follows them, takes out the gang, and rescues Yūna. The story continues as new characters enter Yūna and Mamoru's lives with both good and evil intentions, wacky adventures, hints of romance, and confrontations with the strangest of adversaries. Characters Voiced by: Atsushi Kisaichi (Japanese) Mamoru Kagemori is a plain boy with disheveled hair and thick glasses, which are actually a disguise. He is the son of a ninja family which has been protecting the Konnyaku family for 400 years. He reveals his true self (without glasses) when he transforms into a ninja to protect Yūna from harm and is very lazy except when he's saving Yūna. He has been friends with Yūna since they were children, and has also been in the same class as her since kindergarten. He has a fear of bears, which developed when he tried to protect Yamame from a bear when they were children. His name: Mamoru, means protect in Japanese. Voiced by: Mai Nakahara (Japanese) Yūna is Mamoru's childhood friend and neighbor. She is a quite clumsy and often ditzy girl. These qualities get her into many troublesome situations. Since