In a quiet suburb, three siblings – the intelligent and cunning Samuel, the timid yet brave Jeffrey, and the youngest and strongest, Ninja – have been trained by their grandfather, a master in martial arts, to become true ninjas. As summer approaches, the kids prepare for a vacation filled with adventures while also facing school routines and their own personal challenges.
When a wicked criminal, who has set his sights on the martial arts teacher, learns of the existence of the little ninjas, he decides to kidnap their grandfather to obtain a set of valuable artifacts at all costs. However, the siblings are determined not to let that happen and decide to take action. Armed with their wits and ninja skills, they embark on a daring mission to rescue their grandfather and stop the villain.
As they put into practice everything they have learned, the three ninjas encounter amusing and thrilling situations that test their courage and teamwork. With choreographed fights reminiscent of 90s family comedies, the siblings discover that true strength lies not only in physical abilities but in unity and mutual support. In an epic battle between good and evil, the kids will learn that despite their differences, they can always count on each other, proving that family is the greatest power of all.