Chow Ti is a struggling construction worker living in a partially demolished home with his young son, Dicky, who is just nine years old. Eager to ensure a brighter future for his son, Ti attempts to save enough money to keep Dicky enrolled in private school. Unfortunately, Dicky often faces bullying from his peers, especially from a boy named Johnny, and is ridiculed by his teachers for his worn-out clothing.
One day, while they are at a department store, Dicky pleads with Ti to buy him a popular robotic toy known as CJ1. Ti, unable to afford it, loses his temper and strikes Dicky in front of onlookers, resulting in an awkward and distressing moment for both. Fortunately, Dicky finds solace in the presence of Ms. Yuen, who happens to be passing by. Later that evening, Ti visits a junkyard, his usual spot for salvaging home appliances and clothes. There, he discovers a peculiar green orb left behind by a spaceship and decides to take it home, presenting it to Dicky as a new toy. Dicky is initially skeptical, but later embraces the curious orb.
In a surprising twist that night, the green orb morphs into a adorable alien creature resembling a dog, establishing a bond with Dicky. This charming being, which Dicky names CJ7, possesses remarkable restorative powers, demonstrated when it magically revives a rotten apple. Enthusiastic about the potential of his newfound friend, Dicky imagines CJ7 could help him become popular and excel in school. In one of his dreams, CJ7 is portrayed as a brilliant inventor, crafting unique gadgets just for him. However, when Dicky wakes, he is disheartened to find that CJ7 doesn't quite grasp his wishes, instead causing a series of humiliating mishaps at school, which lead to further scorn from his classmates.
In a moment of frustration, Dicky discards CJ7 in a trash bin, only to realize that he has made a grave mistake. Racing back to retrieve CJ7, he discovers that the garbage truck has already emptied the bin. To his relief, he finds CJ7 waiting for him at home, leading to a heartwarming reconciliation between the duo.
Meanwhile, Ti faces his own set of challenges when he loses his job after an argument with his boss, who wrongly accuses Dicky of cheating on a test. Upon returning home, Ti learns that the accusation holds some truth, leading to an angry outburst where he takes CJ7 away from Dicky, insisting that he improve his grades first. However, the situation takes a positive turn the following day when Ti's boss apologizes and offers him reemployment with a bonus. Tragically, Ti suffers a fall at work and ends up in the hospital, where Ms. Yuen breaks the news to Dicky about his father's demise. Refusing to accept this heartbreaking reality, Dicky rushes home, and in a moment of desperation, CJ7 expends its life force to heal Ti.
The next morning, Dicky awakens to find Ti peacefully sleeping beside him, but in the process, CJ7 has turned into a lifeless doll. Dicky wears CJ7 around his neck as a pendant, a constant reminder of their bond. In an uplifting conclusion, Dicky witnesses a UFO landing on a bridge nearby, and from it emerge numerous alien dogs resembling CJ7, each adorned in various colors and designs, joyfully approaching him, led by one that mirrors CJ7 perfectly.
