In Japan, there's increasing concern about school bullying. Our correspondent Terrence Terashima has the details from Tokyo.

Reports suggest bullying has become a very worrying issue in Japanese schools. According to a government survey, 2018 saw the largest ever number of reported cases, 543,933 in total, a rise of nearly a third on the previous year. 

What's even more alarming, however, is about four in five of these cases are from elementary schools. Experts warn that those who are subjected to continuous bullying from a young age are more likely to suffer from Post Traumatic Stress.

YUKO KUMA CEO, Mamoru Inc. "A definition of bullying has been broadened to account for various forms of harassment, which accounts for the increase. But increased social media use amongst children also plays a big part."

However, while the internet may be to blame for many of the cases, it can also backfire on the bullies.

YUUKI YANAGISAWA "Children of all ages are now using mobile phones, which is possibly contributing to the increase, because of bullying through social networks. But at the same time, it's also proof of harassment."

TERRENCE TERASHIMA Tokyo "Bullying in schools is now becoming a serious social problem in Japan. Many people are blaming the schools and education officials for turning a blind eye, hoping that the problem will go away before it becomes serious. Trying to protect their reputation rather than the well being of the children."

Experts say one of the reasons why school bullying is so endemic in Japan is because of old cultural teachings or how it's shameful to show any sign of weakness.

YUKO KUMA CEO, Mamoru Inc. "It is not easy to say 'Help' in Japanese culture. We have to change that, teach children that it is OK to ask for help. Also, people around them should make an effort to see the signs. We are working on a system where people can report bullying or ask for help anonymously."

Yuuki Yanagisawa, who works with a support group, has experience herself of bullying in schools. She says there's much more to the problem, and therefore the solution, than meets the eye.

YUUKI YANAGISAWA "The best measure against bullying is not trying to find a solution between the victims and perpetrators, but bystanders and schools also have an important role to play. They should not be ignorant, and teachers should function as supervisors."

It may be no surprise to learn that the number of teenage suicides has also increased in Japan in recent years. Experts are calling on the government to take the issue more seriously. Terrence Terashima, CGTN, Tokyo.