“3 Ninjas” was hardly a critical hit, but it did $29 million decent on a budget of $2.5 million, leading to near-instant sequels. Oddly enough, only the first “3 Ninjas” movie was made by Disney, the rest was made by TriStar Pictures.
A second film was made, “3 Ninjas Knuckle Up,” directed by veteran Korean cinema director Shin Sang-ok, operating under the pseudonym Simon Sheen. Shin has had an incredibly eventful life (as documented in Paul Fischer’s 2015 book “A Kim Jong-Il Production: The extraordinary true story of a kidnapped filmmaker, his star actress, and the rise of a young dictator. “), originally making films in an area of Korea that was then under Japanese occupation. During the 50s and 60s, Shin produced numerous successful classics that captured the attention of Japanese audiences. everyone, North Korean dictator Kim Jong-Il.In 1978, Shin and his wife were kidnapped by Kim and “re-educated”, Shin was forced to act in movies for the state.Years later, in 1986, Shin and his wife eventually escaped from Kim while attending the Vienna Film Festival and headed to the United States. “3 Ninjas Knuckle Up” was his last film as a director.
Despite being filmed around the same time as the original “3 Ninjas,” “Knuckle Up” remained on shelves due to several maze distribution deals. It wouldn’t see the light of day until 1995. A second sequel, “Kick Back” by Charles T. Kanganis, was then made, this time with Rocky played by an actor named Sean Fox. and Tum-Tum were replaced by J. Evan Bonifant. Slade is still there. Due to efficient filming, “Kick Back” was first released in 1994. Fans of the Rocky original may be confused by the cast that alternated between the first three films.
https://www.slashfilm.com/950781/why-3-ninjas-recast-rocky-when-it-came-time-for-a-sequel/ Why 3 Ninjas Recast Rocky When It Came Time For A Sequel