Sticking With Who You Know! (Japanese: ピカチュウポッチャマくっつかないで！！Pikachu, Pochama, Keep Apart!!) is the 149th episode of Pokémon the Series: Diamond and Pearl, and the 615th episode of the Pokémon anime. It first aired in Japan on October 29, 2009 and in the United States on March 20, 2010.
As our heroes get closer to Sunyshore City and Ash’s next Gym Battle, they come across a rather large town. After checking in at the Pokémon Center, suddenly Pikachu and Piplup start to act very strange. They grab onto each other with great affection and won’t let go! They seem stuck to each other like magnets, and when Ash and Dawn try to pull them apart, they don’t stay apart for long.
Meanwhile, a Pokémon research scientist named Professor Kodama, with the assistance of Team Rocket, is working on a machine that is supposed to make Pokémon friendlier to each other—similar to using the move Attract. Professor Kodama’s beloved Quagsire and Magnemite appear not to like each other at all, which is the inspiration for the professor’s work. But unbeknownst to him, his machine is working very well on all the other Water-type and Electric-type Pokémon in the area, putting all of them in the same situation as Pikachu and Piplup!
Meanwhile, Team Rocket decides to steal Professor Kodama’s machine. Brock slowly starts to figure out what may be happening, and Nurse Joy reveals to our heroes that she knows the professor’s Pokémon are not getting along. Team Rocket carries out the plan to steal the machine, and take Pikachu and Piplup (still tightly stuck together) for good measure. They attempt to take off in their balloon. But after a struggle with the professor, the machine comes crashing down. The Attract effect immediately stops, freeing all the previously stuck Pokémon—and Team Rocket is sent blasting off again!
Deciding that Professor Kodama’s next project is to figure out precisely why his machine didn’t work on his own Water-type and Electric-type Pokémon, our heroes take their leave and head off once again toward Sunyshore City.
Ash and his friends stop in a large town, deciding to go to the local Pokémon Center. There, Ash decides to train with Pikachu, but as Piplup follows, he runs into Pikachu and they both fall, Pikachu shocking Piplup out of reflex. Piplup gets angry and berates Pikachu. Suddenly, both Pokémon are overcome with attraction as they rush each other and embrace.
Right away, Ash and his friends know something is amiss as Piplup and Pikachu continue to hug. At a nearby building, a scientist works nonstop, the room strewn with research materials as he works on a generator. Team Rocket works on tidying the area, as they were hired by the professor, named Kodama, since they don't have a task. James and Meowth make up an excuse to leave the building, leaving Jessie to clean up the strewn paper notes. Nearby, a Magnemite and Quagsire stare angrily at each other.
Meanwhile, Ash and Dawn's efforts to talk to their Pokémon fail. Ash decides to try to pull them apart, so he and Dawn grab their Pokémon and struggle to pull them apart, but the two seem stuck together. Ash manages to pull Pikachu away by a little, but Pikachu suddenly shocks everyone. Piplup gets hurt too, but he recovers and they go back to hugging again. Brock suggests that Dawn should recall Piplup, so she brings him back into his Poké Ball. Pikachu falls over, his body still posed. Piplup comes out of his Poké Ball and the two return to hugging. Ash and Dawn try to separate them again, but this time Brock suggests to split them and face them away from each other, identifying it as the situation being similar to a magnet, suggesting that having them face away could create a repulsion. It appears to work at first, but they spin back around and hug again. They decide to go to Nurse Joy and as they head inside, Meowth and James notice and decide to watch.
Pikachu and Piplup stuck together
Inside the Center, they find out that other Pokémon have been affected just like Pikachu and Piplup. Brock notices that all the affected Pokémon are in a pair, with one Water type and one Electric type. Nurse Joy mentions that none of the other Pokémon in the center have been affected. Meowth listens in and concludes that Professor Kodama's experiment must be responsible, so he takes James back to the lab. When they return, they find the professor still hard at work. When Meowth asks the professor about his experiment, Kodama reveals that his invention is dubbed the Affinity-Enabler, which broadcasts a form of Attract over an antenna and causes Pokémon to cease any rivalry and become attracted, regardless of gender, but it seems to fail on his test subjects. It doesn't help that the two Pokémon have hated each other for some time. The two battle and cause destruction, but only Kodama's orders cause a ceasefire. Trying to help, he increases the machine's power, which causes the Pokémon at the Center to get even closer and hug more intently.
Brock notices that the two types are opposites and that the situation cannot possibly be natural, being more forced. Kodama continues his work while Meowth suggests that they steal the machine based on what Meowth and James saw earlier. Meowth suggests that they could use it to make Pikachu friendly towards Meowth so they can present it to Giovanni. Another scuffle between Magnemite and Quagsire accidentally hits the machine's lever, shutting the machine off. The effects stop immediately at the Center, making the Pokémon go back to normal. However, Kodama pulls the switch again, reversing the effect. A nearby Trainer mentions that his Raichu never got along with the Squirtle it is attracted to now. Brock believes that the person creating the effect may have a similar situation with two Pokémon hating each other. Joy mentions Professor Kodama and that he has a lab nearby, wanting to make his Pokémon get along, everything clicking into place.
Joy leads them to Kodama's lab as Ash informs him of the situation. Kodama knows that his experiment was indeed successful as he fills them in on his research. Jessie and James try to get Ash and his friends to leave before they break the disguise, Meowth playing with the machine to try to get their attention. However, Kodama spots them and unintentionally breaks their disguise. After reciting their motto, Meowth triggers their balloon and proceeds to steal the machine. Kodama grabs ahold as Team Rocket tries to escape with Ash and his friends in hot pursuit. Kodama hits the switch a couple of times on the machine, flickering the effects. Meowth grabs Pikachu and Piplup with a mecha arm. Quagsire and Magnemite show up and work together, Quagsire launching Magnemite to the balloon. Kodama rides on Magnemite as it shocks the machine, breaking the ropes and causing it to fall, breaking on impact and eliminating the effect. Quagsire uses Water Gun to break Kodama's fall and bring them to safety. It appears that Magnemite and Quagsire never really hated each other, but rather only wanted to use each other for battle training. Ash sends Staraptor to retrieve Pikachu and Piplup, bringing them to safety. Jessie and James prepare to battle, but Pikachu's Thunderbolt and Piplup's Bubble Beam send them blasting off before they can summon any Pokémon. Back at the Center, the Trainers happily leave, with their Pokémon in good shape. Brock mentions to Kodama that since Magnemite and Quagsire were dual-type Pokémon, the machine may not have worked. As Kodama prepares to return to his work, Ash and his friends set off.
The episode's English dub title is based on the phrase "Sticking with what you know".
This episode was aired in the United Statesletterboxed for standard-definition viewers. This is probably due to Cartoon Network stopping their cropping practices sometime after the initial dub airing of the previous episode, as other 16:9 shows on the network which had been cropped for standard-definition viewers, including some episodes of the Pokémon anime which had initially been presented cropped, switched to letterboxed presentation sometime during the week prior to this episode's initial dub airing.
The original English dub title was announced as Sticking With You Know Who!, but this was later changed.
In the Japanese version, Brock mentions that Pokémon with the same gender cannot be attracted to each other normally. This is a reference to the game mechanic.