Looker first appeared in The Final Passage, having arrested several members of the Seven Sages as apart of the International Police. He showed interest in Lexi, citing to his colleagues that she was an ignition flame in his professional career.
Looker next appeared in XY099, after having sent Lexi a letter in XY098 to meet him in Lumiose City. Upon meeting one another, he reveals he had traveled to the Kalos region on an assignment to find and arrest Xerosic Looker signs Lexi on as his assistant in his fight for justice, and the two begin taking on cases together. During their first case, he meets a homeless young girl named Emma and her Espurr named Mimi, whom he decides to take under his wing. He becomes a father-figure to the girl, but because of their poor living conditions, Emma feels she is a burden to Looker and decides to look for a job to help support him. She finds a job at Lysandre Café and her employer turns out to be none other than Xerosic, who uses Emma as a test subject for a special suit that has a cloaking device and can power up any Pokémon the user has. Xerosic remotely controls the suit and makes Emma commit various crimes (although she is completely unaware of what she is doing). Looker and Lexi manage to rescue her, and Looker arrests Xerosic and leaves Kalos. He leaves a letter with Mimi that reveals he has paid for the property in full so that Emma may continue to call the bureau home and use it however she pleases.