Amidst a tree in a night, a Seedot falls down by accident, waking a Shiftry. Seedot falls even more and falls down to a branch. A Nuzleaf is bounced off to a Vileplume, who runs away. The sun comes out and Nuzleaf awakes and is being left alone, as Vileplume runs away deeper into the forest. The Nuzleaf sees it is not where it should be and jumps away, but accidentally falls down from a cliff.
Meanwhile, the heroes continue towards Oreburgh City. Brock sees on his map that the city lies behind a mountain. Ash wants to go there as soon as possible, though Dawn wants to stay in the Pokémon Center nearby. Bonsly cries in hunger and Brock gives it some food. Suddenly, they see a whirlwind. Nurse Joy wants to help a Nuzleaf, but gets attacked by Razor Leaf. Brock runs to defend her and flirts, but gets jabbed. Brock knows that Nuzleaf live in groups than alone, while Joy wants to help it get healed. Brock also knows the Nuzleaf is now afraid and calms it down, then takes steps to gain its trust. Also, he takes a leaf and blows it, making tunes.
Nuzleaf is calmed down, but is still afraid. Brock sends Bonsly to befriend it. Bonsly eats a part of the berry, while Nuzleaf the other part. Nuzleaf and Bonsly eat more of Brock's berries. Joy is amazed by Brock's skills and understands, as she is being told he wants to be a breeder. Brock takes a potion and sprays on Nuzleaf's wound and in an instant the wound is gone. Joy wants to know why is Nuzleaf so far from its home, a tree with many other Nuzleaf, Seedot and Shiftry. Ash, Dawn and Brock promise Nurse Joy to take the Nuzleaf back where it belongs. Team Rocket see this and plan to get the Nuzleaf, as Meowth thinks the boss would like to have the Nuzleaf play the tunes for him.
The heroes wander, with Bonsly and Nuzleaf becoming friends. A Shiftry (which is Meowth in disguise) appears, while Jessie and James (as scoutsmen) arrive to take Nuzleaf *where it should be*. Dawn sees Shiftry for the first time and scans it via PokéDex. This reveals this is Meowth and Meowth tells that it lies and blows the secret. They take their disguises off and take Bonsly and Nuzleaf with them. Brock gets the net they are captured in. Ash sends Staravia, who charges to cut the net. Jessie sends Seviper, who uses Haze to block. Later, Brock is tied to a tree, while Bonsly and Nuzleaf are being put in a cage. Team Rocket are hungry and see that they have not much of food. Brock offers them to cook it and later, it is transformed into some delicious dish.
While they eat, Brock runs away with Bonsly and Nuzleaf. Bonsly uses Double Edge and damages the cage, but hurts itself. Brock tells it can free itself and Nuzleaf, so does another Double Edge and frees itself. With this, Bonsly evolves to Sudowoodo. Staravia did not see Brock, so Ash proposes to Dawn they go to see the site where Team Rocket flew to. Team Rocket are searching for Brock, who took the Pokémon. Brock sees the tree and remembers his mission. He needs to cross a river and calls Sudowoodo back, who does not like water. Nuzleaf is sad because Sudowoodo left, so sends it back. Sudowoodo almost manages to cross the river, but they see Team Rocket.
Jessie sends Seviper and Brock his Coragunk. Seviper bites Croagunk, so Croagunk retaliates with Poison Jab. Seviper goes to use Poison Tail, but gets countered by Poison Sting. A part of the attack damages the balloon and smoke arises, so Ash and Dawn go to check the site. Seviper wraps Croagunk, who attacks it with Brick Break, and, after several hits, manages to take it off. However, both Croagunk and Seviper got defeated. James sends Carnivine, who uses Bullet Seed on them. Sudowoodo sees this and arrives to the other side, though managed to spray itself with water. Carnivine uses Bite, but misses and Sudowoodo uses Double Edge. Carnivine uses Bullet Seed and Sudowoodo counters it with Bullet Seed of its own, as it used Mimic.
Ash and Dawn arrive and see Brock's Sudowoodo. Ash tells him they could help him, but Brock does not want to, as this is Bonsly's first battle as a Sudowoodo. Carnivine uses Bullet Seed and hits Sudowoodo, but gets pushed away with Double Edge. Carnivine bites it and Sudowoodo throws it away with Flail. Carnivine uses Bullet Seed, though Sudowoodo evades and uses Mimic to attack Carnivine with the same attack, defeating it. Jessie sends Dustox and James Cacnea. Ash sends Piakchu and suddenly, a powerful wind blows and Shiftry appears. Meowth persuades that Team Rocket wanted to help Nuzleaf, though the twerps wanted to hinder.
Nuzleaf is taken by Team Rocket, but Shiftry uses Razor Wind to cut the balloon. Nuzleaf falls, though Shiftry uses the wind to put it on the ground. Pikachu uses Thunderbolt to blast Team Rocket off. Ash and Dawn are impressed by Sudowoodo's capabilities. The heroes leave them at the tree, as the heroes go to Oreburgh City.
- The episode's title may be a reference to the television show Leave it to Beaver.
- This is also one of the few times the Japanese title was translated directly, or almost directly.
- Everyone shouts out the title card.
- Music from Lucario and the Mystery of Mew and Jirachi: Wish Maker is used as background music.
- Professor Oak's lecture: Ash's Aipom
- Pokémon senryū: エイパムが しっぽでつかむ サトシのハート Eipamu ga, shippo de tsukamu, Satoshi no hāto "Eipam, it seizes with its tail, Satoshi's heart."
- A teaser for the tenth movie was broadcast after the Japanese premiere of the episode as part of the special broadcast.
- The Japanese ending credited both A Staravia Is Born! and Leave It To Brocko!.
- While the episode aired as part of an hour-long special, the credits were as they would have been had the episodes aired separately. As such, Staravia was featured but Sudowoodo was not.
- This is one of the few episodes of the Diamond & Pearl series where Dawn's Piplup does not appear.
- Ash and Roark narrate the next episode preview, which is one minute long instead of the usual thirty seconds.
- When Team Rocket is eating the food Brock fixed for them, James comments that the food is as good as Nanny and Pop-Pop's.
- This episode features a scene similar to Do I Hear a Ralts?, in which Meowth dresses up as another Pokémon (in this case, a Shiftry) but is exposed when he is scanned by a Pokédex.
- In the scene where Team Rocket is eating the food Brock made, when Wobbuffet eats the food from its fork, as soon as it eats it, another piece of food appears on its fork instantly, without Wobbuffet moving at all.
- When Meowth is lying to Shiftry about who attacked Nuzleaf; he says that Shiftry is the one who harmed Nuzleaf.
- When Brock gave Nuzleaf the Oran Berries in a bowl, there were about 10-15 in the first shot, but in the shot after that, the Oran berries shrunk and multiplied.
- Though Ash noticed Bonsly ate solid food after some time, in AG183 it still ate Brock's food.
- When this episode aired in Japan, along with A Staravia Is Born!, there was no opening, and a cold opening intro. It went straight to the episode after the previous episode finished. In the English version, a cold open intro, possibly made up by Pokémon USA, shows Team Rocket starving, and Brock tied in a tree offers them some food.
- When Dawn sees Nuzleaf, she asks, "Who's that Pokémon?", an obvious reference.