Detective Pikachu is a special kind of Pikachu featured in the Detective Pikachu game. He is not able to use any move unlike other Pikachu but seems to possess a rather high intelligence to the point where he claim to be a renowed detective.
One day, Detective Pikachu encounters a boy named Tim Goodman and after a short talk, the two must chase two Aipom who were causing trouble by harassing citizens. After retrieving a woman's necklace that was stolen by a Burmy who was itself chased by the two Aipom.
After that, Detective Pikachu takes Tim to his house before being wrapped up in a new case after they discover a Glalie attacking two people, they manage to knock the Pokémon unconscious and discovers that the two people are reporters. After encountering a frozen Drifloon and eventually a Drifblim, after solving the case, the two escape from the cave with the help of the Drifblim.