Our story unfolds during the twentieth century first decades. Lili is the beloved daughter of a young army officer who had been sent to the eastern front of battle in Asia. Before leaving to war, his father left her in the hands of his best friend, Master Yuki. Yuki is an ancient professor in the martial arts and he owns a preparation school for ninjas. While living with Yuki, Lili has been taught how to behave and fight as an experienced ninja and she is engaged in the practice with other students in a regular basis, despite her young age (she is eight years old). She is practically a senior herself. To complete her proficiency Lili has to pass a final test and the so expected day arrives at last. She'll be defied by a dozen skilled ninjas and she must fight them all at the same time in Yuki's training Japanese garden.