A total of 395 minors under the age of 18 were abandoned by parents or guardians nationwide in the three years to March, a survey indicated Saturday.
Some of the children died of starvation or heatstroke after being left alone in their homes or in public places.
By fiscal year, 121 children were found abandoned in 2011, 169 in 2012 and 105 in 2013. In some cases, children were abandoned at child care centers, according to the survey.
The plight of abandoned children has drawn public attention since the skeletal remains of a young boy, who is thought to have died at least seven years ago, were found in May in an apartment in Kanagawa Prefecture. The boy's father was subsequently arrested.
Osaka Prefecture was found to have the highest number of abandoned children over the three-year period, at 113. The next highest tallies were 90 in Tokyo and 40 in Saitama, the survey showed.
The fatalities included a 9-month-old boy who died in a cardboard box in his Yokohama home in 2011 while his parents were out all day playing pachinko; a 3-year-old girl who starved to death in Gunma Prefecture in February last year after she was abandoned in an apartment by her mother; and a 20-month-old girl who died of heatstroke after being left at home without air conditioning for 18 hours in the city of Saitama last August.
As local governments differ in the way they classify child abandonment, such as cases when a parent working overnight leaves a child alone at home, the true number of children abandoned may be even higher. Most of these governments limit their definition to abandoned children with identifiable parents, while some also include abandoned infants whose parents were unknown.
The data were obtained in a Kyodo News survey of the nation's 47 prefectural governments and 22 major cities earlier this month.