Japan's 70-year-old Child Welfare Law, has been overhauled, with a new bill coming in in June. This new bill recognises a child's right to grow up in a family setting.

It puts a focus on children being fostered, rather than institutionalised, and experts say it's a first step to making institutions a last resort, rather than the default position.

"The law's revision allows us to think proactively about children's rights, which is a great thing. Some people, foster parents included, tend to get (too) emotional because of their love for their child. But this law is a step forward in that people with different perspectives get together to discuss what's best for the children." said 49-year-old Asako Yoshinari who has three foster children under her care.

"By choosing foster parents over baby homes, and having the child lovingly nurtured and grow up in this environment, I think, is very important in order to create a precedence where people, whether it's the birth parents or the authorities, can see that having a child brought up by foster parents rather than in an institution is better," she added.

Some 85% of the 40,000 children who are unable to live with their parents in Japan are institutionalized. This is by far the highest percentage among rich countries, and has prompted repeated warnings from the United Nations.

A major issue is a lack of awareness about the fostering system, with just 10,200 registered foster families, and adoptions being even rarer, at just 544 last year. Another problem area is that fostered or adopted children are often stigmatised, due to a society that treasures uniformity and blood ties.

A rise in reports of child abuse has also proved a stumbling block. Welfare workers main concern is taking children out of immediate harm, and placing them in institutions is faster than finding a foster family. Welfare workers also have little time to follow up with those children due to the magnitude of the problem, leaving them to languish for years.

"In other countries, the right for a parent to physically punish their children doesn't exist anymore, but in Japan that still exists. It will be necessary to shine a light on that problem where abuse happens in the name of punishment, down the road," said Hiromichi Kinouchi, the Vice Chairman of Japan's National Association of Foster Parents, said.

Japan's goal is family-based care for a third of those children by 2029.