Guardian Ninja Mamoru (Kage kara Mamoru!, literally "Protect from the Shadows!") is a series of Light Novels written by Tarou Achi with illustrations by Sai Madara, which was published from 2003 to 2008 for 12 volumes. It tells the story of teenage nerd Mamoru Kagemori and his childhood friend Yuuna Konnyaku who, being quite The Ditz, gets into trouble quite often.
Good thing Mamoru is secretly a badass Ninja who comes from a family that has been protecting the Konnyaku family for 400 years.
Mamoru has protected Yuna since they were both in kindergarten. When Yuna is in trouble, Mamoru quickly puts on his ninja suit and transforms into a powerful ninja which is often due to Yuna, being both clumsy and dim-witted, ends up stumbling into situations where Mamoru is forced to rescue her.
The novels have a manga adaptation which was serialized in Monthly Comic Alive from 2005 to 2022, and an anime adaptation which aired from January to March 2006 for twelve episodes.
This show offers examples of:
- All Love Is Unrequited: Mamoru shows little interest in any girls. The only one he even considers is Hotaru, before she revealed herself as a rival kunoichi.
- Alternate Character Reading: Mamoru's name, coupled with the usage of "kage" (which can mean "darkness"/"shadows" under 2 different kanji, one of which is in his surname), makes for some great Japanese puns.
- Bad Ass Family: The Kagemori family. Mamoru could handle multiple other ninjas (and aliens) alone easily. His parents are even better.
- Celebrity Is Overrated: Yuna quits her promising idol career because it would take her away from Mamoru.
- Catchphrase:
- The Kagemori family motto "Continuing to protect my neighbor for 400 years!" (with variations as appropriate)
- "Big news! It's big news!" - Airi
- Deconstruction: A family vows to secretly protect their neighbors and all their descendants. Four hundred years later, the bodyguards evolve into a Badass Family perfectly capable to take on any problem... but their neighbors, being protected from anything, never had a chance to learn how to protect themselves... The last descendant is The Ditz at best and Too Dumb to Live at worst.
- Epunymous Title: Depending on the kanji used for "Mamoru", the title can translate to either "Mamoru from the Shadows" or "I'll Protect You from the Shadows".
- Harmless Villain: The aliens - their idea of a crafty human trap is the old basket-with-stick-and-string baited with sushi. Yuna falls for it... sorta.
- Humanoid Aliens: Humanoid reptiles that show up in episode 9.
- I Just Want to Be Normal: Tsubaki really wants to just enjoy life as an ordinary highschool kid.
- Implausible Fencing Powers: Mamoru can deflect bullets fired from a BFG with his sword, Tsubaki can slice anything with hers... except nata de coco...
- Intimate Healing: Hotaru can heal someone's wounds by kissing them on the lips.
- Knight Templar Parent: Mamoru's parents Kengo and Sakurako. They are nice enough most of the time, but when it comes to making sure the Kagemori line will be continued, they become super serious.
- Laser-Guided Amnesia: Yuna gets amnesia at the end of the series and doesn't remember confessing, or that Mamoru is a ninja.
- Legacy of Service: The Kagemori Ninjas. Protecting their neighbors (the Konnyaku family) for 400 years.
- Look Behind You: Yamame successfully used the "Look, it's a UFO" on Hotaru to win a contest.
- Meaningful Name: The character names usually represent something about themselves.
- Mamoru: To protect
- Konnyaku: ...Yeah, the food.
- Mapputatsu: Cuts everything
- Sawagashi: Noisy
- Mundane Utility: Mamoru's parents aren't averse to using their Ninjitsu around the house.
- No Social Skills: Tsubaki, she doesn't know much about how modern day teenagers live.
- Paper-Thin Disguise: Subverted when the lizard-aliens try wearing masks, but it doesn't work.
- Pun: The alien captain is fond of these, and rewards his henchmen for them.
- Punny Name: Chin Panji (sounds like chimpanzee)
- Reset Button: In the ending Yuna loses her memory about confessing and Mamoru being a ninja.
- Scary Shiny Glasses: Kengo whenever he talks about Mamoru's duty to protect Yuna or continuing the family line.
- Stealth Escort Mission: Protecting his unknowing, ditzy childhood friend means that every day is a Stealth Escort Mission for Mamoru.
- Stock Footage: Used whenever Mamoru appears as a ninja.
- Tempting Fate: "There's no way there'd be a flower pot." Of course, there's a flower pot.
- Too Dumb to Live: Yuna. Mamoru is there to make sure she does live.
- Trademark Favorite Food: Yuna and bananas.
- Weaksauce Weakness: Tsubaki cannot cut Nata de Coco (A Jelly derived from coconut milk.)
- The Unwanted Harem: Mamoru considers looking out for Yuna a full-time job so he isn't interested in finding a girlfriend.
- Unlucky Childhood Friend: Yuna loves Mamoru but he doesn't notice.
- Why Did It Have to Be Snakes?: Mamoru fears bears due to a bear attack when he was young.
