A 12-year-old (13 as of The Cursed Tie) boy born on December 2, Garu is a skilled, shy, and somewhat serious-natured ninja, love interest to Pucca, best friend to Abyo. To Pucca's frustration, however, he only rarely returns her affection and usually frantically tries to escape when Pucca attempts to kiss him. He is the only sane person that knows that he is not Pucca's boyfriend, while everybody seems to think that Garu returns the same feelings that Pucca has for him. Garu's feelings are still a mystery to some people but it is quiet obvious how he feels.

Anything about Garu's family is quite unknown except it reveals that in one of the episodes, Garu has a little brother named Gura. So far, he has only been seen once in an episode called Gura in Town. No real mentioning of his family was made either except for Tobe frequently mentioning his ancestors. One thing revealed, Garu is trying to restore his family name.

Despite trying to avoid pucca's advances toward him, Garu's feelings are truthful shown in a caring but not too affectionate towards her. Interestingly enough, one can come to two separate conclusions about the truth of Garu's feelings depending on which series one chooses to follow. In the original Flash cartoons, it was suggested that Pucca and Garu were officially a couple, and he occasionally gave her boxes of chocolate and other gifts. In one episode, he melted down his beloved sword to make a little ring for her, and in another, he left a rose on her windowsill. The TV series, on the other hand, has hinted that he does care about her to some extent (i.e. getting very defensive when someone insults her like in the episode the Band Played Rong he got upset when Tobe Called Pucca Stupid), but it has never been implied that his feelings for her are more than platonic. In truth, however, it is said that Pucca and Garu are in a boyfriend/girlfriend relationship. It's just that Pucca is a bit too "friendly", unlike Garu, who doesn't want to show "unnecessary" affection.( He only fell in love with Pucca in the episode Full Moon Pucca because he was moonstruck).

Like Pucca, Garu is capable of superhuman athletics and endurance (such as running around the entire world without tiring), yet she still manages to get the best of him. Like Pucca, he does not talk at all in the TV series, continuing to only use the sounds from the Flash cartoons. It's explained in the TV series that he's taken a vow of silence. However, in the episode "Romancing the Clone", Garu's clone speaks throughout the entire episode in an obnoxious manner, but only because the clone was accidentally sprayed with a dishonor potion made by Jumong who let Tobe try to spray Garu with it.But, in the episode, Rootin Tootin Ninja's while accitentally rolling down the moutain with Abyo,(that pucca had made earlier in the episode) it is heard that Garu actully mumbles "Get off me". This is the only time where Garu is heard saying a sentence. Also to note, in the episode Trial by Fury, the judge (Master Soo) says "Sheesh, I thought the guy would never shut up," after Garu takes the stand during the trial, although this was done in a comedic and light-hearted fashion. In Secret Santa Garu at one point was about to read aloud to Tobe (disguised as Santa at the time) his list of things he wants for Christmas but Tobe cut him off as he triggered the trap he sent for Garu. In "Hooray for Bollywood", he and Pucca actually both sing. He also cries and screams in pain from breaking his leg in A Leg Up. In Tobe's nighttime troubles, though technically may not count as him talking, a cuckoo clock at one point opens to reveal a small wooden figure of him saying in his voice "Cuckoo" In Romancing the Clone, Garu has a skill called the "Garusion Illusion", allowing Garu to split into many clones and confuse his enemies.

Garu has been shown to immediately accept a quest if told it will bring him "great honor". The reason for this, although not revealed in the TV series to date, most likely stems from one of Garu's ancestors bringing dishonor upon his family (as was revealed in the original Flash cartoons). In addition to being a skilled fighter, Garu has also demonstrated the ability to play the erhu. Another example of Garu's talents, he has attained the status of 'Fire Wasp Ninja,' becoming a member of the legendary group by the same name.

As though to compliment Garu's talents as a ninja, several female characters have been in love with him: Pucca, Ring Ring, a Swiss girl named Heidi (although Heidi has only appeared once in the television series), the queen of the giant termites (who appeared in the episode Chop Chewie) and a female rabbit who lived inside Santa's magic hat (who appeared in the episode Abru Ca Pucca), which would suggest that he is rather attractive, and said by the nick-name "Handsome". Also, the show's english theme song states he is "a pretty boy".

Unlike Pucca, Abyo, and Ching, Garu lives independently, living a small house just outside Sooga Village with his pet cat Mio. Garu's house as revealed to carry booby traps and other mechanical objects in House of Doom with the traps and object either triggered by Garu by activating certain switches or activated automatically when certain items in the house are removed or touched in any way.