In A Shockingly Cheeky Friendship!, Serena chose Fennekin, received a Pokédex, and started her journey. Serena was then offered to choose her starter Pokémon. However, to Serena's disappointment, Ash had already left Lumiose City for the Santalune City Gym the previous day. Immediately upon arriving, Serena questioned the Professor about the boy on television and he confirmed that it was indeed Ash Ketchum. Serena began her Pokémon journey in A Battle of Aerial Mobility! when she set off to Professor Sycamore's lab in Lumiose City. The next day, while feeding Rhyhorn, Serena thought aloud that something interesting was going to happen and that it involved Ash. On the screen, she saw Ash trying to calm down a rampaging Garchomp at Prism Tower and recognized Ash as a boy she had known in her childhood.
She sat down to watch a news report on an incident that was occurring in Lumiose City. Later that evening, Serena complained about her earlier practice leaving several scratches on her face. However, Serena's attempts at controlling her mother's Rhyhorn ended with her being sent crashing into the ground. In Lumiose City Pursuit!, she attempted to practice Rhyhorn racing after being encouraged by her mother, a famous Rhyhorn racer herself. Serena debuted in Kalos, Where Dreams and Adventures Begin!, where she was forcibly woken up by her mother's Fletchling. Afterwards, she returned to Kalos, bringing along the handkerchief and the memory of her meeting with Ash. However, when Serena's knee continued to hurt, Ash told her "Don't give up till it's over" and helped her up before escorting her out of the forest. Noticing her knee injury, he pulled out a handkerchief and wrapped it around her wounded knee, saying that it is a good-luck charm and that the pain would go away. Then, she met Ash Ketchum, who was looking for the same Poliwag and spotted Serena. One day, while at the camp, she got lost in a nearby forest and was startled by a Poliwag, falling over and hurting her knee.