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Ken (Japanese: ケン Ken) is a member of the Pokémon Mystery Club. Along with his partner, Mary, they try to solve the mysteries of Pokémon origins.
They believe that Pokémon came from space, and are out to prove it.
Ken first appeared in Wish Upon a Star Shape. A spacecraft carrying Cleffa, Clefairy and Clefable had crashed, and a lone Cleffa had fallen out. Ken and Mary wanted to capture the Cleffa so they could study where it came from. Concerned about what Ken and Mary would do to Cleffa, Ash had his Phanpy take care of Cleffa and make sure it got to its spacecraft safely. Phanpy did its job perfectly, and the Cleffa evolved into a Clefairy so it could get on board the spacecraft as it flew away. Ken and Mary, along with Team Rocket were sent blasting off.
Ken also appeared in Crazy as a Lunatone. He and Mary were now trying to capture a Lunatone and studied it. Just like the last time, they were sent blasting off without getting any information about the Pokémon they tried to capture.