Pokémon the Movie: I Choose You! is available in: French European Spanish Portuguese Polish English [Original] on Netflix UK
This is the story of how Satoshi and Pikachu first met. At first, Pikachu was disobedient towards Satoshi, but Satoshi only wanted to be friends with Pikachu. On the day they set out from Masara Town, both of them saw a Ho-Oh flying and they made a vow to meet it.
When Ash tries to pick his first Pokémon on his birthday, he ends up with a stubborn Pikachu and they embark on a journey to find the legendary Ho-Oh.