Originally one of Professor Sycamore's Kalos starter Pokémon, Harimaron quickly earned a mischievous reputation. Its gluttonous nature was starkly displayed when it stole and greedily devoured an entire basket of Serena's macarons, overshadowing its potential. Harimaron's pivotal moment came when Team Rocket captured Professor Sycamore, Serena, and Eureka. Following a trail of macaron crumbs to their hideout, it revealed unexpected tracking skills. Though initially focused on recovering the pastries, Harimaron recognized the threat and intervened against Team Rocket's Mega Mega Nyarth mecha. Using Tackle and Pin Missile, it strategically combined its Tackle with Pikachu's attack to overcome the machine, proving decisive during the crisis and forging a bond with Citron. Sensing a connection and impressed by its courage, Citron accepted Harimaron as his Pokémon when it expressed a desire to join him. Professor Sycamore formally transferred ownership, providing Citron with Harimaron's Monster Ball. As Citron's partner, Harimaron's known battle techniques include Tackle, Pin Missile, and Vine Whip, the latter also used for practical tasks like gathering bamboo leaves. Its personality retains an established fondness for pranks and food.