A camera crew has arrived at the Cerise Laboratory to interview Ash and Goh. After telling about various things they've encountered together as research fellows, including a case involving a group of Diglett, they wrap up the interview by telling about their goals: Ash's goal is to battle Monarch Leon in the World Coronation Series, and eventually become a Pokémon Master, while Goh's goal is to catch every Pokémon in the world in order to understand them better and thus work his way up to understanding Mew, which is said to possess the genes of all Pokémon, showing off some of the Pokémon he's caught so far.
Once the interview concludes, Goh's Sobble, who had stopped by to watch it unfold, resumes its training by target shooting various objects around Cerise Park with its Water Gun. After saving Oddish from a falling Sitrus Berry, Sobble suddenly evolves. Simultaneously, Goh gets a notification of Sobble's evolution on his Rotom Phone while seeing the camera crew off at the laboratory's front door, and rushes back inside to see his newly evolved Drizzile. Drizzile, meanwhile, is feeling happy about its evolution, until it sees its reflection on a pond's surface and realizes it didn't become an Inteleon like it had thought, causing it to become depressed. Goldeen and Poliwag attempt to cheer it up by spraying some water on it, with little success.
Ash, Goh, and Chloe are having trouble finding Drizzile, so Goh asks his Cinderace to help them find it. In the meantime, Drizzile is trying to find a nested spot to withdraw to, only to find every such spot already occupied by another Pokémon. When it is sent flying by Heracross for having disturbed Pinsir, it ends up bumping into Cinderace, who reports back to Goh and shows him to the small cave that Drizzile retreated to. Goh tries to call Drizzile to come out, but when his calls go unanswered, he crawls into the cave himself, finding Drizzile lying down in a small cavern. He tries to ask it to come out so they could train and help it become an Inteleon, but it refuses to move. Cinderace follows Goh into the cave and carefreely drags Drizzile out for Ash and Chloe to see. However, it then sheds a single tear and turns invisible before their eyes. Goh tries to follow its movements through rustling grass and opening doors, but loses it once it's walked out of the laboratory's front door.
Back inside, Ash, Goh, and Chloe discuss the matter with Professor Cerise, Chrysa, and Ren. Chrysa shows them Drizzile's Pokédex entry, which mentions it being intelligent but lazy. Professor Cerise explains that evolution can greatly affect a Pokémon's personality, which reminds Goh of the personality changes his Cinderace went through during its evolutions, going from a happy Scorbunny to an aloof Raboot, and then back to carefree and cheerful with its second evolution. They still wonder, however, why Drizzile acted like it did, and while theories like nesting itself in preparation for its next evolution are thrown around, Professor Cerise says that they don't know for certain.
Goh decides to go search for Drizzile again, and Ash and Chloe tag along. However, by sunset, they've not seen a trace of it. As Goh wonders why Drizzile would want to nest itself, he's suddenly reminded of something from his own past, and realizes where Drizzile could be. He, Ash, and Chloe run to a dilapidated building on a hilltop. On its rooftop, they indeed find Drizzile, looking up at the starry night sky.
Goh sits down next to Drizzile and apologizes for forcing it out of its cave earlier. He explains that, as a child, he didn't want to play with other children in the school playground, and his teacher would keep asking him why he wasn't doing that. He hadn't even known himself why he didn't want to do it, so constantly being asked "why" left him frustrated. Since his parents were almost constantly working and his grandmother was not easy to ask advice from, he had just gazed at the stars for comfort. He had figured that if Drizzile was feeling the same way as he was back then, it'd probably come up here to do the same. Since it had done exactly that, it proves that he and it are alike. Goh assures that, having rethought things, he'll now respect Drizzile's choices and let it stay in its cave as long as it feels like it, hoping that when it's finally ready to be with someone, he could be with it again. Goh suddenly finds himself crying, but Drizzile wipes away one of his tears and smiles at him, before disappearing again. Goh stands back up and heads back to the Cerise Laboratory with Ash and Chloe.
The next day, Goh goes to check Drizzile's cave again, and is happy to find it inside. He comes back out and shares the happy news with Ash and Chloe, before heading out to eat. He promises to his other Pokémon that he'll come play with them once he's done, thinking of how he'll someday be able to play with Drizzile too.