A young girl named Fei Fei is captivated by the legend of the Moon goddess Chang'e, who took a potion for immortality and, as a result, ascended to the Moon to wait for her beloved Houyi. As the annual Moon Festival approaches, Fei Fei, at the tender age of seven, along with her family, prepares mooncakes for the village. Life takes a tragic turn when her mother falls ill and gifts her a white rabbit named Bungee before passing away, leaving a profound impact on the young girl's heart.
Fast forward to Fei Fei at age thirteen; she clings to her belief in Chang'e even four years after her mother’s death. However, she is disheartened to discover her father is engaged to Ms. Zhong, which complicates her emotions further as she has to deal with Ms. Zhong's lively eight-year-old son, Chin, and his pet frog. During the Moon Festival celebration, memories of her mother flood back, triggering a spark of inspiration as she decides to construct a rocket shaped like a rabbit lantern, intending to journey to the Moon to prove that Chang'e truly exists.
With her ambitious spirit and a design powered by fireworks, Fei Fei's rocket nearly achieves lift-off until she realizes that Chin has secretly tagged along, resulting in their imminent crash to Earth. Out of the blue, they are whisked away by a mystical beam of energy and land on the enchanting Moon, where they are soon rescued by two friendly winged foo dogs and taken to Lunaria.
Upon arrival, they meet Chang'e and her fabulous backup dancers, the Lunettes. Chang'e reveals to Fei Fei that she was expected to bring a special gift to reunite her with Houyi. Fei Fei, eager to capture proof of Chang'e’s existence, takes a photo with her, but in an unexpected twist, Chang'e snatches the photo away and insists on receiving the mysterious gift. Confused and frustrated, Fei Fei is determined to uncover what this gift could be.
Feeling disgruntled with Chin, she ventures off on her own, hitching a ride with the Biker Chicks towards the crash site. Meanwhile, Chin encounters some Lunettes and gets taken captive by Chang'e, who challenges him to a game of ping pong for the gift's location. To everyone's surprise, Chin triumphs, yet Chang'e's sorrow over her lost love creates further turmoil as she laments that she may never see Houyi again.
While Chin is imprisoned, Bungee follows the Jade Rabbit into Chang'e's domain. As Fei Fei continues her quest, she meets Gobi, an exiled Lunarian who helps her navigate the complexities of Lunaria. In a series of unfortunate events, Fei Fei discovers her Chang'e doll has been damaged by the Biker Chicks, but she eventually stumbles upon a broken half of a jade circle within one of her mooncakes—an object mirroring what Chang'e wears, which leads her to the realization that this is indeed the coveted gift.
With Gobi's assistance, she reunites with Chin and Bungee, and together they present the broken jade circle to Chang'e, who reconstructs it into a full circle. Briefly reunited with Houyi, Chang'e faces the painful truth that accepting the past is crucial; as he encourages her to move on, she falls into despair, shrouding Lunaria in darkness.
In a heartfelt moment, Fei Fei and Chang'e bond over their shared grief, and they inspire each other to embrace the love surrounding them, ultimately restoring light to Lunaria. A grateful Chang'e grants Fei Fei and Chin safe passage back, while Bungee decides to stay on the Moon with the Jade Rabbit. As Fei Fei returns home, she learns to welcome her father’s marriage to Ms. Zhong and grow fond of her new step-brother Chin.
Fast forward a year, and Fei Fei, now fourteen, embraces her new life happily. During the Moon Festival, she sits with her father, gazes at the Moon, and watches as cranes ascend towards it, symbolizing hope and new beginnings.
