Masanori Kuwasashi is a Japanese game designer and creator best known as the original creator behind the fighting game franchise The King of Fighters. His career began in the video game industry, where he was brought into the company SNK by game designer Takashi Nishiyama after Nishiyama saw his work at the developer Irem. Kuwasashi's first project at SNK was Baseball Star Professional, during which he met Toyohisa Tanabe, who would later become the battle designer for The King of Fighters series. Kuwasashi served as the director for the first entry in the franchise, The King of Fighters '94, released in arcades in 1994. This game established the series' core identity as a crossover title featuring characters from SNK's existing properties such as Fatal Fury and Art of Fighting alongside new original characters, and introduced the team-based 3-on-3 battle system that became the franchise's signature mechanic. The success of this game launched The King of Fighters as SNK's flagship franchise and led to numerous sequels and spin-offs across multiple console generations.

Beyond his work as director and creator of the game series, Kuwasashi is credited as the original creator for several anime and manga adaptations of The King of Fighters. The original net animation The King of Fighters: Another Day, a four-episode series released between 2005 and 2006 serving as a prequel to the game The King of Fighters: Maximum Impact 2, lists Kuwasashi as its original creator. He holds the same credit for the manga The King of Fighters '94, a four-volume series based on the first game, which was published starting in 1995 with story and art by Tatsuya Shingyoji. He is also credited as the original creator for The King of Fighters 2003, a Chinese manga adaptation. These credits appear as uncredited in some sources, but consistently identify Kuwasashi as the originator of the intellectual property on which these works are based.

Kuwasashi's creative involvement extends to character creation within the series. He created the character Omega Rugal, the enhanced boss form of the recurring antagonist Rugal Bernstein introduced in The King of Fighters '95. Rugal Bernstein, the original final boss of The King of Fighters '94, has become one of the most iconic villain characters in fighting game history, known for his devastating Genocide Cutter technique and his role as the organizer of the King of Fighters tournament. Kuwasashi is also credited as the creator of the series protagonist Kyo Kusanagi, the fiery high school delinquent who serves as the central figure of the Orochi Saga story arc.

Outside of The King of Fighters franchise, Kuwasashi worked as the main game designer at the developer K2 on Tenchu: Return From Darkness, an enhanced director's cut version of Tenchu: Wrath of Heaven released for the Xbox in 2004. In an interview about the project, he discussed his approach to refining gameplay balance, adding new cutscenes, incorporating Xbox Live functionality for online cooperative and versus play, and enhancing graphics with higher polygon counts and specular lighting. Kuwasashi stated that the team approached the Xbox version as a second chance to improve upon the original PlayStation 2 release. His work spans both original creation and adaptation, establishing foundational elements of a major fighting game franchise while also contributing to the expansion of existing properties into new media and platforms.