Kinniku Tatsunori was a great fighter of the Kinniku Clan and the father of Kinniku Mayumi, as well as the brother of Nemesis. He appears in a series of flashbacks throughout the series, but plays a more prominent role in Kinnikuman (2011) . The KIN Mark is on his forehead.
Mayumi Kinniku tells a story to Kinnikuman during the finals of the 21st Chojin Olympics: The Big Fight, where he describes how Tatsunori Kinniku was a great warrior.  During one war, he was almost captured and those that captured him sought to remove his mask, but - in an act of self-defence - he used a technique called the Muscle Curtain. He was punched and kicked for several days straight, but he never once lowered his arms or let down his guard. Eventually, the enemy gave up and he was able to preserve his mask. 
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However, as explained by his brother Nemesis in the Perfect Origin Arc, the story of how he used the Niku Curtain - to protect his mask - was a cover up meant to hide the fact that Tatsunori had to use the Niku Curtain to defend himself in a coup against him, led by the ministers from the last king's reign.
While it's established in Kinnikuman Nisei that he created the Niku Curtain and founded the Royal Kinniku Family, this is retconned in the Perfect Origin Arc, with Silverman instead being credited with the creation of the Niku Curtain and the Kinniku Clan itself: however, the same story arc details how Tatsunori was able to perfect the teachings of Silverman, both improving the Niku Curtain, both preaching and spreading the concepts of "mercy", "justice" and "kindness" that set apart the Justice Chojin from the Perfect Chojin and the Akuma Chojin.
Despite Nemesis was far superior to Tatsunori in technique and sheer force, Tatsunori was able to become a king because of his heroic mindset, setting the standard for a future planet and clan of heroes of Justice even when the legend of Silverman faded.
In the anime he uses the Kinniku Guard for 3 months to protect his mask during a Space Samurai invasion on Planet Kinniku.
- His name comes from Tatsunori Hara.
|Brocken Jr., Buffaloman, Geronimo, Kinnikuman, Robin Mask, Terryman, Warsman, Wolfman,|
|Chaos Avenir, Gazelleman, Kevin Mask, Mantaro Kinniku, Seiuchin, Terry the Kid|
|Bibimba, Fiona, Jacqueline Muscle, Okan, Sayuri Kinniku|
|Kinnikuman, Bibimba, Mayumi Kinniku, Sayuri Kinniku, Mantaro Kinniku, Ataru Kinniku, Tatsunori Kinniku, Sadaharu Kinniku|
|Horumon Clan, Churrasco Clan, Muscle Clan|
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|Planet Kinniku, Fire of Inner Strength|