When watching the original Japanese trailer for Pokémon: The First Movie, almost nothing looks like the final product that made it to theaters. Sure, Mewtwo appears in one shot, but throughout the entire trailer, none of the footage looks like it came from Pokémon: The First Movie. Instead, it centers around a set of characters who do not exist in the final product. This begs the question: was there a version of Pokémon: The First Movie that the public never saw?
What Happens in the Trailer for Pokémon: The First Movie?
The first Japanese trailer for Pokémon: The First Movie is entirely unlike any of the other trailers. The shorter segments in the middle seem more in line with the style of the final version of the movie, though specific visuals differ from the final product. One shot of Misty and Brock indicates that, at some point, Mewtwo's island was being torn apart in a storm. At one point, Team Rocket appears top either a tank or battleship lined with cannons.
The more unusual parts of this trailer are art are in pastel-style scenes at the beginning and end. These scenes show new three characters gazing at the clouds as they pass in the form of different Pokémon. One is the movie character Miranda, another looks like an older version of Misty and the third figure is a pink-haired child. They smile, hold hands, walk around and look happy. Ash's Pikachu joins the group eventually, leaping into the arms of the young child.
The Rewrites of Pokémon: The First Movie
The reason for the drastically different trailer is that Pokémon: The First Movie was going to be a drastically different film, possibly serving as a conclusion to the Pokémon anime. However, two things occurred during production that drastically altered the trajectory the film would take.
The first issue is the controversial Porygon episode. Originally, the episodes of the anime showcasing Mewtwo would have aired before the movie's premiere, but the Porygon controversy resulted in everything being shuffled around and restructured. This meant that the whole film needed to be rewritten and expanding in order to introduce all the necessary plot components. Many changes occurred during this rewriting phase, which explains a lot of the smaller differences between the trailer and the final product.
Pokémon: The First Movie Was Going to Be The End of Pokémon
However, the big change came when they decided that Pokémon: The First Movie would no longer serve as a series finale. For some time, Takeshi Shudo, the anime's former head writer, planned on using the film to end the franchise. In a blog, Shudo wrote he intended on ending the first film with Ash as an old man, looking back on his life, only to be reborn as his 10-year-old self, starting off on a new adventure.
This ending was dismissed, however, when the Pokémon franchise became too popular to end. The film became just another entry in Ash's greater adventures rather than its conclusion. It is easy to theorize that the trailer showcases an epilogue to the film, featuring a future where Misty is raising a kid who Ash's Pikachu intrinsically trusts. A logical assumption would be that Ash and Misty had a kid, and this pink-haired child is that kid, but things are not that straightforward.
At the 2019 Anime Expo premiere of Pokémon: Mewtwo Strikes Back -- Evolution, Kunihiko Yuyama, the director of every Pokémon film thus far, discussed the original trailer. During the panel, he confirmed that the women in the trailer, including the one who looked like Misty, had been designed for the trailer. Any similarities to Misty were completely unintentional.
This indicates that these unusual-looking trailer scenes were designed specifically for the trailer, not for the movie. This leads to the conclusion that the trailer was designed to be more impressionistic of what Pokémon: The First Movie was supposed to be rather than representative of any completed product. There is no hidden unmade alternate version of the film, only tossed-out scripts.