Bright Lights, Big Changes! (Japanese: コンビ解散！？サトシとロトムSplitting Up the Combination!? Satoshi and Rotom) is the 98th episode of the Sun & Moon series, and the 1,037th episode of the Pokémon anime. It first aired in Japan on November 25, 2018 and in the United States on March 28, 2019.
When Rotom Dex catches a continuity error during the filming of Alolan Detective Laki, the cast and crew are so impressed that they invite it to join the show and help Laki solve cases! Ash is thrilled, until he realizes the international shooting schedule means Rotom will have to leave…
While our hero sadly considers this option, a serious conversation with Laki reminds Rotom that its real dream is to be the best Pokédex in the world—and when Ash tries to be strong and send his friend off to pursue an acting career, it decides to stay and study rare Pokémon with him instead!
Laki is in the midst of filming another scene for his hit television show, Alolan Detective Laki. Just as he is about to explain the vital evidence to a group of five suspects, Rotom, with its blonde Laki wig, interrupts to correct one of Laki's lines. The director yells "Cut!" and an assistant tells Rotom not to interrupt filming. Ash tries to retrieve Rotom, but Rotom begins a spiel. Another assistant checks Rotom's claims and confirms that a Trumbeak feather was found at the crime scene in the Mermaid's Necklace case and not a Pikipek feather. When Rotom boasts about being a true Alolan Detective fan, Laki tests it with a series of trivia questions, and is impressed after Rotom answers all of them correctly. After Laki shakes hands with it, Rotom is sent into a photo frenzy. The show's producer, George Charino, approaches and goes on to hand Ash and Rotom his business card. George formally invites Rotom to star in Alolan Detective Laki, leaving the Plasma Pokémon speechless. Over lunch, George explains to Ash that they have just started filming season five of Alolan Detective Laki. With the series going on for so long, George is looking for a way to keep things interesting – a new character. George explains that Rotom fits the criteria, and Laki and his Smeargle agree. With the support of its idol, Rotom enthusiastically accepts the offer and agrees to play Laki's newest partner.
The following day, Ash reports the news of Rotom's new role to his classmates at the Pokémon School. Mallow and Lana are thrilled, while Ash admits that he is becoming tired of Rotom's non-stop Laki impersonations. Rotom retaliates and mimics Ash’s voice; Rotom then imitates Kiawe when he's fired up, which Kiawe fails to recognize as himself and instead finds it creepy; and Rotom finishes off with an embarrassing, over-the-top, cutesy imitation of Mallow, causing her to turn red from embarrassment and angrily retort that she would never say those things while Lana tries not to laugh. After seeing Rotom's incredible mimicry, Sophocles comments that Rotom lacks any individual appeal. The blunt comment strikes Rotom's core and leaves it speechless. Sophocles puts on a pair of sunglasses and explains to Rotom that a first-rate actor has their own appeal and an understanding of character. The girls reaffirm Sophocles advice – that Rotom should just be its regular self. The class decides to practice several Alolan Detective Laki scenes with Rotom, with Ash playing Laki, Pikachu as Smeargle, while Kiawe and Turtonator act as the antagonists. Ash goes off script and challenges Kiawe to a battle, but Mallow stops the rehearsal. Everyone praises Rotom for at least staying in character.
Later, Rotom and Laki practice the scene where the pair decide to join forces and solve mysteries together. George is pleased with Rotom's performance, but points out that it will need to add more gestures to make its acting more impactful. Rotom happily accepts the criticism and is thrilled when George reveals that Rotom role will be called "Rotom, the Amazing Pokédex". George makes an even bigger announcement - the production team will be filming overseas for the next season. Rotom is excited, but then notices Ash standing in shock. George explains that they will likely be overseas for half the year, but that time may extend to years if audiences like the series development. Ash is furious and refuses to let Rotom leave him. Rotom replies that Ash never caught it, and that it's technically free. Ash throws two Poké Balls at Rotom in frustration, however the Pokémon dodges and swats them away. Ash storms off, with his Pokémon trailing behind.
Ash returns to the Pokémon School in a sulky mood the following day. His classmates immediately notice Ash's odd behavior and that Rotom is missing. Professor Kukui enters the classroom and escorts the class outside to study Pokémon feathers. Ash, with a stick in hand and his Pokémon walking behind him, leaves the group to begin his own feather expedition. The class are left perplexed and Kukui signals that something has is amiss with Ash. Pikachu soon spots a yellow feather on the ground and Ash then asks for Rotom to identify it. Ash quickly realizes that Rotom is no longer with him. Elsewhere, Laki finishes a new scene and returns to his actor's chair to relax. In the other chair, Rotom lies in exhaustion. Laki asks it about his performance, and Rotom wakes up and exclaims that it was perfect. Rotom then perks up after Laki invites it over to his house to get to know each other better.
Komala rings the school bell to announce that the school day is over. As Ash is leaving, Lillie stops him so the pair can talk. Lillie and Ash head down to a beach, while Pikachu and Snowy play. Lillie explains that Kukui told everyone that Rotom will be traveling overseas to film the next season of Alolan Detective Laki. Lillie empathizes with Ash and adds that she felt the same while her mother was busy working and living away from the family. Ash reflects on the highs and lows spent with Rotom since he first arrived in Alola and affirms Rotom's earlier claim to freedom. Lillie assures Ash that Rotom stayed with him on its own free will and that the pair made a great team. She then suggests that Ash talk to Rotom to smooth things over, and Ash agrees to the idea.
In Laki's apartment, Rotom examines Laki's memorabilia. Rotom soon stumbles on an odd poster, to which Laki explains was from a play before he hit the big time. Laki tells Rotom that he almost considered quitting acting because he received little to no lines, but he continued to follow his childhood dream. Rotom is instantly reminded of Ash's sentiments and ambition to become a Pokémon Master. Laki then asks Rotom about its dream, but the Pokémon doesn’t reply. Meanwhile, Ash lies awake in bed and continues to think about Rotom.
The following day, Ash and his Pokémon make their way onto Laki's latest filming location. Laki reveals that Rotom is hiding behind his actor's chair, and pushes it and Ash to talk things over. Ash apologizes to Rotom for yelling and admits that he will support Rotom's ambitions. Rotom replies that it will stay and won't pursue its role in Alolan Detective Laki. The revelation shocks Ash and Rotom assures him that its goal is to become the best Pokédex in the world. Rotom adds that it will stay with Ash because he is the most likely to encounter rare Pokémon. Laki and Smeargle admire the now reunited duo for their strength and teamwork.
During a night on the couch, Kukui, Rotom, Ash and Pikachu watch the latest Alolan Detective Laki episode. Rotom reminds Ash to not fall asleep, but the young Trainer looks drowsy. The episode reveals that a Chatot will be fulfilling Rotom's role as Laki's latest companion. The episode ends with Laki, Smeargle, and Chatot returning to Alola. Ash and Pikachu are shocked, but Rotom explains that George decided that the overseas filming location was to be a one episode feature to avoid having to change the series' name.
The clapperboard that Mallow holds up has the number "98" written on it, which could be a reference to this episode being the 98th episode of the Sun & Moon series. However, in the English dub, it is only the 97th due to SM064 being skipped.