Rob Letterman (Goosebumps) is directing the project, which is due to start shooting this month in London.

The concept of Pokemon sees players acting as trainers who collect cute but powerful monsters called Pokemon in order to compete in battle tournaments.

Pikachu is a species of Pokemon, while Detective Pikachu the character is a peculiar sort from the Pikachu set, a self-styled investigator who is good at finding things.

The story is set into motion when Smith's character's father is kidnapped, forcing the teen to team up with Pikachu in order to find him.

Watanabe will play a character named Detective Yoshida.

Nicole Perlman and Alex Hirsch wrote the script with Eric Pearson and Tom McCarthy having completed production polishes.

Mary Parent and Cale Boyter are producing for Legendary. Joe Caracciolo Jr. and Pokemon’s Tsunekazu Ishihara are executive producing. Legendary’s Alexandra Mendes will co-produce.

Watanabe’s work is well-known at Legendary as he appeared in the company’s Godzilla and the upcoming sequel Godzilla: King of Monsters.

The actor was nominated for an Oscar for his work in the Tom Cruise drama The Last Samurai, appeared in Batman Begins and has a voice role in Wes Anderson’s upcoming Isle of Dogs.

He is repped by WME and ROAR.