Pokemon The Series: XY episode 9 - Capture Miare Gym! Citron's Secret!
Upon returning to Miare City, the group meets up with Citron and Eureka's father Limone who reveals to Satoshi and Serena that Citron is Miare City's Gym Leader. Limone also reveals that the Citroid, a robot Citron had built to look after the gym in his absence, has gone haywire. Satoshi and Citron infiltrate the gym to beat the Citroid in a Pokémon battle to take back the Miare Gym.