Mario was initially conceived as an Italian plumber by Shigeru Miyamoto, a renowned game maker, during the development of the game Donkey Kong. The name Super Mario is quite common in Italy, much like other names such as Super Marco, Super Antonio, Super Alessandro, and Super Roberto. In fact, if you were to visit Italy in your lifetime, chances are you'd come across a man named Mario. It's possible that Miyamoto chose this name either based on his travels in Italy or perhaps due to an Italian plumber who worked at his place.
Regardless of how the name came about, once the character of Mario was created, people instantly fell in love with him. The image of a plump little man jumping and running around was highly entertaining. However, Nintendo faced a significant challenge when it came to trademarking the name "Mario" as it's a common name, and it's generally not possible to trademark common people or place names.
To overcome this hurdle, Nintendo decided to rebrand the game character as "Super Mario" so that it could be sold as a legally protected commercial product. The company has since developed various games like Super Mario, Super Wario, and Super Mario World, all of which are licensed under Nintendo. But they could never trademark the name "Mario" alone.
This is a common issue in the gaming industry. For example, games like Super Angry Birds and Super Candy Crush Saga have trademarked names that are unique and distinct. If you're the CEO of a game-creating company, it's crucial to remember to select a name that is not related or similar to any existing games.
When it comes to the naming of games, Google Android and Apple iOS have different approaches. Google, in particular, has been somewhat lackluster in this regard. Since Google isn't even a country, it often follows rules similar to those of Apple-Mac in the USA, which can sometimes lead to naming and intellectual property-related problems.