Ash is alone in the forest after losing at the Snowbelle Gym. Serena tracks him down, but they end up in a shouting match, and she runs off after angrily telling Ash to start acting like himself again!
Soon, a snowstorm sets in, and Ash takes shelter in a cave with some frightened Pokémon. He gets into trouble while trying to help a stranded Spewpa—but Greninja shows up just in time, and then shifts effortlessly into Ash-Greninja to rescue Spewpa!
When our heroes reunite, Ash promises not to overdo it again—a promise Greninja soon has to enforce when Ash learns the Kalos League is coming to Lumiose City!
After losing to Wulfric during the previous episode, Ash is sitting alone in the Winding Woods, thinking about his recent defeat. Nurse Joy reveals to his friends that his Greninja also ran away, though she tells them that its strength was back to normal after its defeat. They don't know where Greninja went, but Serena guesses that it ran off to find Ash. Tired of waiting, Serena decides to find Ash herself. Bonnie asks her brother if Ash will be back, with Clemont responding that there's no need to worry. Pikachu releases Talonflame, Hawlucha, and Noivern from Ash's belt and asks them to find Ash, as he is worried about him. Meanwhile, Team Rocket is spying on Ash and wondering what is up with him, realizing this will be the perfect time to capture Pikachu. Greninja is also thinking about its recent battles and defeats, and wondering what it did wrong. Serena finds Ash in the woods, and tells him that he can talk to her about anything that is bothering him. She tells him that she understands from her experience from the showcases, only for Ash to start yelling at her, claiming that she doesn't know how he feels. Upset with Ash, Serena throws snowballs at him, saying that the Ash she knows always tries his best and never gives up. She runs off crying after the argument, as she wants the real Ash back. This causes Ash to realize what Serena is talking about and decides to return to the Pokémon Center. Unfortunately, he rolls off the side of the mountain, getting lost in the process.
Pikachu and Ash's other Pokémon are still searching for their missing owner, and Bonnie is now wondering where Serena vanished off to. Serena returns, still upset with her scuffle with Ash, with the siblings wondering why she is huffy. Nurse Joy tells the group that a snowstorm is coming through, and they need to get back. Pikachu asks Serena about saving Ash, with Serena reluctantly agreeing to help out. Ash takes shelter in a cave, while Pikachu and the others try to look for him. Pikachu encounters Team Rocket and uses Thunderbolt, though it only electrocutes them. The trio decide that getting Pikachu isn't really worth it, as his shocks aren't as powerful, and Giovanni wouldn't be too happy. Serena and the group find Pikachu, but they see that the storm is getting worse and they need to find Ash very soon. Squishy detects a Zygarde Cell and runs off to find it, with Pikachu following its trail. However, the cell vanishes, but the group finds a cave. Serena regrets scolding Ash earlier and tells the group that she really admires Ash and didn't want to see him down. Clemont tells that they all admire Ash, and they'll continue looking for him after the storm dies out.
Meanwhile, Ash is resting in a cave when he notices an Oddish, Budew, Sentret, Zigzagoon, and Scatterbug out in the cold, and subsequently invites them inside. He gets an instant flashback memory of his younger days, as this reminds him of the time he offered some wild Pokémon shelter. Squishy decides to find Ash while the group is asleep, though Pikachu notices a sound. Ash notices a group of Spewpa sitting on a tree branch out in the cold, and decides to rescue them. Greninja meets up with Squishy and points out where Ash is heading. While Ash is just about to rescue the last Spewpa, the branch breaks off, making them both fall off, though both are rescued by Greninja. However, a gust of wind causes Spewpa to be blown out of Ash's hand. Greninja transforms into Ash-Greninja and rescues it.
Inside the cave, Ash tells Greninja about what happened prior to his Trainer days, similar to what happened earlier. When Ash got lost, he rescued some Pokémon before a rainstorm hit them, and stayed with them inside a tree until the storm ended. This was what inspired him to become a Trainer. Ash apologizes to Greninja about what happened at the gym battle. He realized after spending some time, that a team is not someone who has to do it alone, but together. Ash tells Greninja that they should start their training again, as a team. Once the storm subsides, Ash and the group of Pokémon came out of the cave, with the group of Spewpa evolving into Vivillon, and they fly off into the sky. Later, the duo reunite with Serena and the others. Ash apologizes about leaving and before Serena could do the same towards Ash, he thanks her for snapping some sense into him. Squishy contacts the other Zygarde Cells about Ash and Greninja's combined teamwork. Team Rocket reappears, with the intention of stealing Pikachu, with the latter blasting them off with a Thunderbolt. Surprisingly, they are happy that a full-throttle Thunderbolt blasted them off, as Pikachu is back in full strength.
The next morning, the Kalos League is revealed to be held in Lumiose City. Just as they're about to leave, Greninja offers its Poké Ball to Ash, as a reminder of their friendship. Ash promises that they will reach the Kalos League.