The following information comes from a Game Informer interview with Miyamoto...

- despite what the Hollywood film says, Mario and Luigi do not have last names
- Miyamoto feels different characters can take on different roles in each game
- this is why Mario and Bowser fight in the main games, but race together in Mario Kart
- Miyamoto compares this to the Popeye series and how those characters took on different roles
- Miyamoto views Mario and other characters as one big family, or maybe, a group of actors
- Miyamoto does consider Yoshi's Island as part of the Mario series
- Chargin' Chuck throws baseballs because Nintendo wanted variation in attacks, but had to work within resources. Decisions were made that seemed a bit weird due to these restrictions
- Mario's natural hair color is brown
- the hair color choices were made due to limitations on the NES
- Miyamoto sees Mario as a blue-collar worker, and this is generally the only rule he follows when putting Mario into various roles
- Miyamoto does admit that seeing Mario as a doctor may seem a bit unbelievable