Takashi Tezuka in the context of "Super Mario"

Super Mario Bros. is a 1985 platform game developed and published by Nintendo for the Nintendo Entertainment System (NES). Directed and produced by Shigeru Miyamoto, it is the successor to the 1983 arcade game Mario Bros. and the first game in the Super Mario series. Players control Mario, or his brother Luigi in the multiplayer mode, to traverse the Mushroom Kingdom to rescue Princess Toadstool from King Koopa (later named Bowser). They traverse side-scrolling stages while avoiding hazards such as enemies and pits and collecting power-ups such as the Super Mushroom, Fire Flower and Starman.

Miyamoto and Takashi Tezuka designed Super Mario Bros. as a culmination of the team's experience working on Devil World and the side-scrollers Excitebike and Kung Fu. Miyamoto wanted to create a more colorful platform game with a scrolling screen and larger characters. The team designed the first level, World 1-1, as a tutorial for platform gameplay. Koji Kondo's soundtrack is one of the earliest in video games, making music a centerpiece of the design.

Bowser (Japanese: クッパ, Hepburn: Kuppa; "Koopa"), also known as King Bowser or King Koopa, is a fictional character and the main antagonist of Nintendo's Mario franchise. In Japan, he is titled Daimaō (大魔王; Great Demon King"). He is the arch-nemesis of the plumber Mario and the leader of the turtle-like Koopa race. Depicted as a fire-breathing monster with a tyrannical personality, Bowser's ultimate goals are to kidnap Princess Peach and conquer the Mushroom Kingdom.

Bowser debuted as Mario's opponent in the 1985 video game Super Mario Bros. Designer Shigeru Miyamoto initially conceived him as an ox based on the Ox-King from the Toei Animation film Alakazam the Great. However, Takashi Tezuka remarked that the character resembled a turtle more than an ox, leading them to redesign Bowser as the leader of the turtle-like Koopas. Since 2007, Bowser has been voiced by Kenneth W. James.