Din Song is a hardworking college student living in Shanghai, who harbors a deep longing to reconnect with his childhood friend, Li Na. She moved away ten years ago with her father, Mr. Wang, and now enjoys a life of luxury. One day, an old man gifts Din a mysterious teapot, which releases a wish dragon named Long. Long reveals to Din that he will grant him three wishes, making Din the tenth and final master he has served. In return, fulfilling Din's wishes will free Long from his servitude, allowing him to enter the Spirit world.
However, Din's newfound hope quickly turns tense when he finds himself pursued by a trio of goons, led by Pockets, who are sent by Mr. Wang to retrieve the teapot in an attempt to salvage his failing business. To escape, Din uses his first wish to combat the goons effectively.
The following day, Din and Long show up at Li Na's birthday celebration. Din wishes to transform into a wealthy princeling for just one day, hoping to catch Li Na's attention and revive their friendship. Yet, Li Na is disheartened upon discovering her father's absence from the celebration. As "Dan," Din comforts her, and they are invited by Mr. Wang via video call to share a meal together. Long cautions Din that the moment Li Na learns of his true identity and financial status, she would likely abandon him.
During their date, Din seeks Long's guidance on behaving according to his new persona but inadvertently hurts Li Na’s feelings. When the goons start pursuing Din again, they flee back to Din's old neighborhood, where he reveals his true self to Li Na. They reminisce about their shared childhood adventures, but Li Na ultimately withdraws, insisting she has obligations to fulfill, which leaves Din heartbroken.
In a fit of anger, later that night, Din demands Long make him wealthy, yearning for respect and validation. Long discloses his own tragic past; he was a powerful lord, punished by the gods for his selfishness with a fate of becoming a wish dragon to learn an important life lesson.
Meanwhile, Pockets manages to double-cross Mr. Wang, seizing the teapot for himself and wishing for everything he touches to turn to gold. During this chaos, he mortally wounds Mr. Wang in front of Li Na and engages in a confrontation with Din. On Long's back, Din faces off against Pockets. In a climactic moment, Long willingly puts himself in harm's way to save Din, turning Pockets into a gold statue. The ensuing struggle results in both Pockets shattering upon impact with the ground and Long being swept away by the river.
As Long finds himself at the gate to the Spirit world, he is tempted to enter but chooses instead to plead with the guardian to return to Din for his final wish. The guardian agrees, provided Din uses his last wish to heal Mr. Wang. Upon fulfilling this wish, Long must depart.
In the wake of these events, Mr. Wang opens a restaurant that showcases Din's mother’s culinary expertise, with both Din and Li Na actively contributing. One day, Din unearths another teapot resembling the one Long inhabited and sets him free once more. Long informs Din that his return to Earth comes with the obligation of serving ten additional masters before truly being free. After a heartfelt farewell, Din watches as Long disappears, leaving the teapot with the elderly guardian from the beginning, who is revealed to be the gatekeeper to the Spirit world.
