Ikue Otani is a Japanese voice actress and singer, most famous for providing the voice of Pikachu in Pokémon. She took pregnancy leave from her work from January to May 2006, but her voice credit for Pikachu did not change, as her voice has been recorded many times.
Ash, Misty, Brock and Pikachu face Mewtwo, a bioengineered Pokémon, and the super Pokémon it has created. But little do they know that these super Pokémon are far more powerful than any old Pokémon.