What is that funky KN symbol, anyway?
Here’s the skinny of what it is. the NK symbol should be read right to left, as a KN symbol- the symbol of the Kinniku royal house. Every member of that house has it somewhere on their body, as a birthmark. Kinnikuman’s is on his rump. The symbol was developed as a mock of the “JP” or “PJ” symbol for a company that produced pencils. An example of the KN symbol can be seen Here.