Almost all ghosts in Japan are women or children. In a still male dominated society, those who cannot defend themselves from the fury of angry men are subject to the terrors that drive the innocent to the events leading to ghostdom. Anguish and vengeance in life are the precursors to becoming a yurei or ghost in Japan. Men are less likely to suffer the anguish than women or children encounter in their daily lives - even today.
Despite this thread being about ghost children, women by far comprise the most common type of ghosts found in Japanese literature for a thousand years. Many demon types and supernatural beings (yokai) are also female, with more examples of female among folklore beings than in other societies such as in Europe. Kitsune, yuki-onna, rukio kube are among the many female monsters of Japanese lore.
Part of the issue, is that in 'normal' Japanese society, the men are in charge, most people are law-abiding, there is an understanding of hierarchal social standing - anything that falls outside of the expected way the world worked (anything 'outside') is considered horrible.
Women and children being the source of terror is so counter to that kind of thinking, that they become the most horrible representive of the 'other'.
Does that make sense?
