Kinnikuman is a constant whiplash of "virgin" and "chad".

He's a coward,get's beaten for most of the match and barely has any luck with women.And barely has any interest in fighting.
But when it gets personal he goes all out and manages to outsmart his opponents too,with some luck.
Despite being above many other fighters because he's from a superhero race, he has to take his responsibilities and being a good example to everyone who watch him(there are times where he lost because he was too naive). He starts as a tokusatsu/Superman parody but gets more mature over the years.

Plus add that the villains make the Naruto ones look weak in comparison,he suffered a lot.

The think i love more about Kinnikuman its the style, old manga like Saint Seiya and Jojo has this style over substance, unicquenes and charisma to it, every character is insteresting at least visually and makes you interested in each fight