I believe that people who play games around 20 know the name of Mario’s character, but probably few people know that the name Mario is actually the name of the “old landlord” of Nintendo.
Mario was originally called “Jumpman” or “jumping person”, at the beginning of Nintendo’s early stage of business, financial constraints, and difficult situation. While the game makers were bothered by finding the right name for the new game character, the angry landlord Mario Segale broke into the long-awaited rent and made a fuss, eventually being persuaded to leave. At that time, the president Arakawa and the developers agreed. Decided to change the character Jumpman in the upcoming game to the name of the landlord – Mario.
The origin of the name of Mario’s brother, Luigi, is more “casual”, which is derived from the homonym of “similar (るいじ)” in Japanese.