Muramasa is a character of the day who appeared in Wired for Battle! (EP142).
In the past, Muramasa was an elite Pokémon Trainer, but became tired of winning and decided to open up an elite Pokémon Training School, located between Cherrygrove City and Azalea Town. His skills and experience attracts students from around the world.
However, Shingo, his son and one of his top students, believed that he could predict the outcome of any battle with the help of his laptop. Muramasa stalked the nearby forest in search of a viable opponent for Shingo, and after seeing Ash and Pikachu, he invited them to his school. His hunch was correct, as Ash and Heracross eventually battled Shingo and defeated his Scizor. After thanking Ash for a great battle, Shingo decided to train harder underneath Muramasa.
(Source: Bulbapedia)
