XY140/Plot

makes a phone call to and, although he first has to deal with  saying hello a little too close. Delia thanks, , and for accompanying Ash on his Kalos journey, and they assure her the pleasure was theirs as they've learned a lot from traveling with him and had a lot of fun too. Ash tells his mom that he has a lot of stories to tell and will be starting the trip back to Kanto that afternoon, and Professor Oak assures him they'll be waiting. Delia wishes her son a safe journey, and extends an open invitation to Serena, Clemont, and Bonnie to visit anytime. The call ends, and Ash tells Pikachu that it's time to start getting ready, making Bonnie start to realize their journey is indeed about to come to an end.

Later, the gang tuck into lunch; however, Serena notices that Bonnie has barely eaten anything. Bonnie shrugs it off by claiming to have eaten too many sweets earlier, and as Clemont begins to remind her about not eating just before meals, the doorbell rings. The gang find that, Alain, Mairin, and Chespie have arrived, with Sycamore telling them that he just called to say a final goodbye before Ash and Serena leave.

Jessie, James, and make a report to  detailing how they single-handedly brought down Team Flare and destroyed the Giant Rock, thanks to doctored footage, while claiming that their goal was their entire reason for coming to Kalos in the first place. Giovanni tells them that it's obvious they did play a role in stopping Team Flare and congratulates them on a job well done before ordering them to report back to the. The three then celebrate with their Pokémon that the altered footage worked and that Giovanni is pleased with them, before rushing off to catch the first plane back to Kanto.

Ash is surprised to have been told that Alain and Mairin are leaving on a new journey to Frost Cavern as part of Professor Sycamore's research. Sycamore explains the discovery that the Sundial is now emitting energy whenever sunlight shines on it that can be used to pin down the location of Mega Stones, meaning that there should be a Mega Stone somewhere in Frost Cavern. Mairin explains that many other locations have been identified too, all of which will be checked out as part of her and Alain's investigation. Ash then notices that Alain is no longer wearing his Mega Ring, and Alain explains that because he had received it from Lysandre, he gave it to the authorities to use as evidence, knowing full well that he would no longer be able to Mega Evolve his. Alain tells Ash that he has decided to follow his example and start from scratch with the intention of finding the Mega Stone on his own, and hopes that one day when they're both strong enough again they will battle once more. Ash promises him that they will, and the two friends bid each other a final goodbye. Chespie says farewell to Clemont's Chespin, who begins to cry. Mairin thanks Serena for her help in rescuing Chespie from Lysandre Labs, but Serena shrugs off the thanks by saying that Mairin played as much of a role as she did. Sycamore tells the gang before he leaves that he looks forward to reuniting with them all one day, and the gang bid him, Alain, Mairin, and Chespie goodbye. Ash then realizes it's time for them to prepare to leave too, causing Bonnie to become sad again.

At Lumiose Airport, the gang discover that Serena's flight to Hoenn will be leaving before Ash's flight and decide to take the chance to let out all their Pokémon to say farewell, warning them that they may not see each other again for quite a long time. There are many fond farewells among the Pokémon, with much sadness and tears. walks up to to say goodbye; however, Dedenne can't bring himself to. Bonnie sadly tells him that they need to say goodbye, but Dedenne begins to get upset and instead escapes from Bonnie's arms and runs through the airport. Giving chase, and using Pikachu's electricity, they track down Dedenne who is hiding behind a video monitor. Everyone asks Dedenne to emerge but he refuses to. Bonnie tells him she understands how he feels because she feels exactly the same; she feels very close to everyone and their Pokémon and her dream is that they could all stay together forever. However, she explains that she understands that Ash and Serena have their own dreams and they need to leave to pursue them, just as she has her own dream of one day becoming a Pokémon Trainer with Dedenne as her partner. She hopes to one day defeat Serena in a Pokémon Showcase and win against Ash in a Pokémon battle and knows that saying goodbye is just another step on that journey, and so that's why they should be happy, too, since it brings them all closer to their dreams. Dedenne is still upset, but emerges and jumps into Bonnie's arms. Ash asks Dedenne to help Bonnie achieve her dream and looks forward to facing Bonnie in a battle someday, although he doesn't intend to lose. Serena concurs, promising to face and try and win against Bonnie in a Showcase. Clemont also looks forward to when he can face her in a Gym battle. This helps both Dedenne and Bonnie to cheer up, knowing they still have a lot to look forward to.

Soon it is time for Serena to leave. She thanks Ash, Clemont, and Bonnie for all of their help throughout her first journey. Clemont asks her to call them occasionally, while Bonnie tells her she'll come and find her once she's started her journey. Serena then tells Ash she's glad she sought him out when she began her journey and that he is her ultimate goal. Ash is briefly taken aback. She vows to seek him out again someday as a more mature woman, and Ash voices his approval. As Serena is carried down the escalator, she quickly turns around again, asking for one last thing from Ash. She runs back up the escalator and is seen leaning in towards Ash, but her farewell is not shown directly. As the escalator pulls her back downwards again, Clemont, Bonnie, and Pikachu are stunned and blushing. Ash's face remains blank for a while, while Serena is also blushing as she moves away. Serena thanks them, and they all recover to bid her an enthusiastic farewell. Outside the airport, Ash, Clemont, and Bonnie watch as Serena's plane leaves. Clemont hopes Serena will be okay, and Ash assures him that she'll be fine and will become stronger in Hoenn. Clemont also promises to become stronger and invent devices that will help people and Pokémon. The three have some more time before Ash's plane leaves, so Clemont has a request for Ash before he leaves; he wishes to end their adventure in Kalos as it began: with a. Ash happily agrees, and sends Pikachu up against as Bonnie watches. The two Trainers, as would be expected, battle to their hardest.

As the sun sets in Kalos, Clemont and Bonnie watch as Ash's plane flies away. On a bright sunny day in Hoenn, Serena arrives, ready to begin a new adventure as she recalls her previous adventures: choosing as her starter Pokémon, meeting  and, finding her calling as a Pokémon Performer, and getting a chance to strive for the title of. At the Prism Tower, Clemont works on an invention (assisted by Clembot) as he remembers meeting Ash, getting to invent various devices, reuniting with, eventually facing Ash in a Gym Battle and having to sacrifice his first Clembot to help defeat Team Flare. Bonnie recalls all the Pokémon she got to meet throughout the journey and formed special relationships with:, , , and Squishy. At his lab, Professor Sycamore helps a choose his first Pokémon before taking a call from Alain and Mairin. In Frost Cavern, Alain, Mairin, Charizard, and Chespie take in the wonderful sights as Alain looks forward to his fresh start. At the ruins of the Lysandre Labs, Sawyer is living his dream as he assists with his investigation of the site. In a forest,, , and enjoy meeting the various Pokémon that live there. At, continues its role as caregiver as it breaks up a squabble between a  and a. Nearby, destroys another vine made of negative energy while being watched over by Squishy and Z2, continuing its role as protector of Kalos.

On his plane, Ash looks out at the passing seascape as he recalls his adventures in Kalos: arriving in the region with Alexa, making new friends and meeting new Pokémon, defeating Gym Leaders, finding new rivals, going on new adventures, meeting with Team Rocket various times, deepening his relationship with Froakie and eventually unlocking the power of the Bond Phenomenon, making it to the finals of the Lumiose Conference against Alain, and destroying the Giant Rock and taking down Team Flare with the help of the Gym Leaders of Kalos, Diantha, Steven, Malva, and. He then recalls his final goodbye with Greninja, before leaving him so he could meet his own destiny.

It is the middle of the night when Ash arrives at the outskirts of Pallet Town, and the young Trainer spends a few seconds regarding his hometown before continuing. Arriving home, he sees the lights are still on and knows his mom is waiting. Taking a moment to reflect that they have another wonderful adventure behind them, Ash and Pikachu enter the house ready for the day when they'll go on their next Pokémon journey.