Plot
For generations, the storks of Stork Mountain delivered babies to families around the world, until one stork named Jasper imprinted on an infant girl and attempted to keep her for himself. Jasper accidentally dropped the infant's address beacon, shattering it, and went into exile. Unable to deliver the orphaned girl, the storks adopted her under the name Tulip. CEO stork Hunter discontinues baby delivery in favor of online package delivery with Cornerstore.com.
Somewhat of an outcast, the creative Tulip tries to promote new ideas for Cornerstore, which consistently backfire and cause the company to lose stocks. On her eighteenth birthday, Hunter declares her to be a severe burden and liability due to this incompetence. Hunter explains to Junior, his top employee, that he is being promoted to chairman, and so he chooses him to take his place as boss, exciting Junior. Hunter assigns Junior with firing Tulip before being promoted to boss. Despite being desperate to prove himself, Junior cannot bring himself to do so and instead fraudulently transfers Tulip to the abandoned mailroom, which hasn't been used since the storks stopped delivering babies, under the pretence that she must sort letters, whilst informing Hunter that he was successful in firing Tulip.
Meanwhile, a 4-year-old young boy named Nate Gardner, who lives with his workaholic parents Henry and Sarah, is lonely and wants a younger sibling. Unaware that the storks stopped delivering babies, he sends a letter to Cornerstore and it reaches Tulip, who enters the defunct baby factory and inserts the letter into the baby-making machine, causing it to create a pink-haired infant girl. Junior injures his wing trying to turn off the machine. Afraid that Hunter will fire him, Junior agrees to accompany Tulip and secretly deliver the baby to her family using a makeshift flying craft that Tulip invented. They eventually crash, escape a pack of wolves that fall in love with the baby, and reach civilization, during which Junior and Tulip bond with the baby and name her Diamond Destiny. Junior shares that he doesn't know why he wants to be in charge, and Tulip confesses she built the plane to try and find her family by herself, as well as a single piece of her homing beacon she wears as a necklace. Meanwhile, Henry and Sarah open up to Nate's desire for a younger sibling and bond with their son by building a landing platform for the storks.
Junior and Tulip encounter Jasper, who had followed them from Stork Mountain. Jasper apologises for 'orphaning' Tulip and shows her that he has nearly repaired her delivery beacon, but is missing one piece, which had been in Tulip's possession for years. Junior, at first attempting to send Tulip on her way without hurting her feelings, is forced to confess to Tulip that he was supposed to fire her and that there is nothing left for her at Stork Mountain. Feeling saddened, Tulip leaves with Jasper to meet her family while Junior continues alone to deliver Diamond Destiny. Cornerstore's pigeon employee Toady learns about Diamond Destiny and informs Hunter, who reroutes her address beacon and leads Junior into a trap. Hunter has Diamond Destiny taken away to live with penguins in order to silence the incident and prevent more plummeting stocks while Junior is tied up and gagged.
Tulip reunites with Junior and frees him. They return to Stork Mountain during the highly anticipated Storkcon event to save Diamond Destiny from the penguins. When they are cornered in the baby factory by Hunter and the other stork employees, Junior sends millions of archived letters from families into the baby-making machine, causing it to rapidly produce babies and distract the storks. Hunter seizes control of a giant crane and tries to destroy the factory, but Diamond Destiny finds the crane's controls and causes Hunter to lose control and cut the lines holding Cornerstore on; Cornerstore and Hunter fall off the mountain. As a final resort, he makes an attempt to take Junior and Tulip down with him. Junior manages to save themselves by flying again, his dislocated wing popped back into place with Tulip's help.
In the aftermath of Cornerstore's destruction, Junior rallies the storks to deliver all the babies to their families around the world. Junior, Tulip, and Jasper deliver Diamond Destiny to the Gardners. Nate is at first disappointed about not getting a brother but quickly cheers up upon seeing his new sister's ninja skills. Tulip finally meets her missing family, and Junior continues working as the co-boss at Stork Mountain.
