Kinniku Ataru (キン肉アタル, Kinniku Ataru) is a character from Yudetamago's manga and anime series Kinnikuman and it's sequel Kinnikuman Nisei. He is the elder brother of Suguru Kinniku and the uncle of Mantaro Kinniku.
- Classification: Seigi Choujin
- Homeland: Planet Kinniku
- Age: 34, 68 (Nisei)
- Height: 197 cm
- Weight: 102 kg
- Choujin Kyoudo: 1,080,000 Power
- Trademark Techniques: Napalm Stretch, Face Flash, Ataru's Muscle Spark
- Trainer: Mayumi Kinniku
- Blood Type: O
- First Appearance: Manga Chapter 272, Anime 2 Episode 1
Ataru is the older brother of Kinniku Suguru, the protagonist of the series, and the eldest son of the Royal Kinniku Family.
In his childhood he could not endure the strict Spartan-like training his parents put him through and ran away from home. Because this all happened before Suguru's birth, Suguru was never aware of Ataru's existence.
Ataru watched over his little brother from the shadows as he fought against Evil Choujin, making sure he learned the value of friendship, and then returned after 25 years during the Survivor Match for the Kinniku Throne.
Ataru possesses what he refers to as True Friendship Power (真・友情パワー, Shin Yuujou Pawaa) and his own Kajiba no Kuso Djikara prototype called Gouka no Kuso Djikara (業火のクソ力, Fiery Inner Strength) (Ganso Kajiba no Kuso Djikara (元祖・火事場のクソ力, Original Burning Inner Strength) in the anime).
- Shigeru Chiba in Kinnikuman: Scramble for the Throne, Kinnikuman Muscle Generations, and Kinnikuman Muscle Grand Prix Max
- Eiji Takemoto in Kinnikuman: Nisei
- Tetsu Inada in Kinnikuman Nisei: The Path of the Seigi Choujin (Game Boy Advance game)
- Eric Stuart in Ultimate Muscle (English Dub)
- Napalm Stretch (ナパーム・ストレッチ)
- Ataru's Muscle Spark (アタル版マッスル・スパーク, Ataru-ban Massuru Spaaku)
- Face Flash (フェイス・フラッシュ)
- Niku Curtain (肉のカーテン, Niku no Kaaten)
- Dragon Suplex (ドラゴン・スープレックス)
- Jungyaku Jizai no Jutsu (順逆自在の術)
- Borrowed from The Ninja.
- Choujin Lightning Strike (超人稲綱落とし, Choujin Izuna Otoshi)
- Borrowed from Ashuraman.
- Red Rain of Berlin (ベルリンの赤い雨, Berurin no Akai Ame)
- Borrowed from Brocken Jr..
- Buffalo Hammer (バッファロー・ハンマー)
Ataru was born the eldest son of the Royal Kinniku Family and was first in line to become the next king of Planet Kinniku. But Ataru grew tired of their life of constant training, and left home to let his brother grow up to be the next ruler of planet Kinniku. Throughout Kinnikuman's career as a Seigi Choujin, Ataru was watching him, hoping he would learn the value of friendship. Eventually, Kinnikuman had proved himself worthy to inherit the throne after winning numerous championships and defeating many powerful evil choujin. However, five other "Kinnikuman" came forward claiming to be the true heir to the throne of planet Kinniku--they had all been born in the same hospital, and because of a fire they had been mixed up so the true heir might have been misplaced in the chaos. In truth, they had been chosen as the Five Fated Princes by five evil gods who feared Kinnikuman's power should he assume the throne. A survivor series tournament was organized to determine the true ruler.
Ataru went to Fujiyama and killed one of the Princes, Kinnikuman Soldier (キン肉マンソルジャー), who'd been selected by the God of Brutality, and stole his mask to be able to compete and help his younger brother prevail. He asked Buffaloman, Brocken Jr. Ashuraman, and The Ninja) to join his team, but they refused until they saw him save a little boy from an Evil Choujin. Calling themselves the Choujin Blood Brigade (超人血盟軍, Choujin Ketsumeigun), they were given a buy into the second round and headed for Nagoya Castle, where they were pitted against Team Phoenix. After both The Ninja and Ashuraman lost to Satan Cross, Ataru, Brocken, and Buffaloman met Kinnikuman Super Phoenix, Prisman, and Mammothman in a six-man tag match. The match took place in a floating cube with three separate rings on it.
During the match Ataru used the Face Flash and Niku Curtain, causing Mayumi and Sayuri to figure out his identity. He also spoke to Suguru of True Friendship Power. Brocken and Buffaloman managed to take Phoenix's allies out of the match at the cost of their lives, causing Ataru to hit Phoenix with a fury of his teammate's techniques. However, Super Phoenix tore Ataru's page out of the Muscle Prophecy Book and had Mammothman burn it. While disappearing, Ataru used a Muscle Spark on Super Phoenix to show his brother a move powerful enough to defeat Super Phoenix. Super Phoenix quickly regained the upper hand and defeated Ataru with his Muscle Revenger, and Ataru fell to the ground and disappeared.
Neptuneman gathered Ataru's ashes and used them to save Geronimo from being killed by The Omegaman's Omega Catastrophe Drop. The ashes appeared again and held up a flag to catch Bibinba when she threw herself from the stands. Ataru's spirit, along with those of Robin Mask, Neptuneman, and Geronimo appeared during Suguru's match with Super Phoenix and restored his Kajiba no Kuso Chikara (Burning Inner Strength) to him. Ataru and the others were restored to life when Kinnikuman used his Face Flash following his victory over Super Phoenix.
In Nisei, Ataru has no known offspring and has been gone from Planet Kinniku for awhile, having formed the team of the Choujin Untouchables (超人警察隊（アンタッチャブル）) with The Ninja. But when he hears of the situations involving his nephew Kinniku Mantarou, he returns home with The Ninja and puts Mantarou through "Kajiba no Kuso Djikara" training, sending him to a prison island to fight No Respect (Bone Cold, Hanzou, and Fork the Giant).
- Alias: Kinnikuman Soldier
- Family: Tatsunori (grandfather), Mayumi (father), Sayuri (mother), Suguru (brother), Nemesis (uncle), Mantaro (nephew)
- Other: Left-handed
- 1st Kinnikuman Nisei Popularity Contest(9th place)
- 1st Kinnikuman Nisei ~All Chojin Dai Shingeki~ Popularity Contest (15th Place)
- Chojin Blood Brigade: Captain
- Eldest Son of the Royal Kinniku Family
- Chojin Untouchables
- Fighting Devil (戦鬼, Senki)
- Win/Loss Record (Singles)
- O Woolman (Napalm Stretch)
- O The God Shark (Napalm Stretch)
- O Bulldozerman (Napalm Stretch)
- O Heavy Metal (Napalm Stretch)
- O Kinnikuman Soldier (Napalm Stretch)
- O Bockman (Napalm Stretch)
- X Kinnikuman Super Phoenix (Muscle Revenger→ Prophecy Page Burnt)
- As his brother Suguru was named after Yomiuri Giants player Suguru Egawa, Ataru's given name comes from Egawa's older brother Ataru.
- His age was originally given as 29, which would make him 5 years older than his Suguru, even though flashbacks showed him to have been at least in his late teens when Suguru was a baby. His age was later changed to 34 to fix that.
- In the English Dub, he is known as Sargent Muscle