For generations, the storks of Stork Mountain delivered babies to families around the world, until one stork named Jasper attempted to keep an infant girl for himself. Jasper accidentally destroyed the infant’s address beacon and went into exile. Unable to deliver the orphaned girl, the storks adopted her under the name Tulip. CEO stork Hunter discontinued baby delivery in favor of package delivery with Cornerstore.com. 18 years later, Tulip, now a young adult, tries to promote new ideas for Cornerstore, which backfire and cause the company to lose stocks. Hunter assigns top delivery stork Junior to fire Tulip so he may be promoted to boss. Junior cannot bring himself to do so and instead transfers Tulip to the mail room.
Meanwhile, a young boy name Nate Gardner, who lives with his workaholic parents Henry and Sarah, is feeling lonely and wants a younger sibling. 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 shut down the machine. Afraid 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. On the meantime, Henry and Sarah open up to Nate’s desire of a younger sibling and spend time with their son by building a landing platform for the storks.