Now That's Flower Power! - S6.E33

After arriving in Slateport City, May begins her training for the Contest. However, just as she and Beautifly have some good results, a boy named Drew appears and starts belittling May. May does not give up and has a battle with Ash. Despite losing, a man named Mr. Big appears and teaches May about Contests. He takes them to the shop, where he finds May's Torchic had eaten his Bluk Berry, which is to be used in tonight's firework event. In order to make amends, May goes with her friends in search for the berry.