Seventy-nine education systems worldwide have restricted smartphone use in schools. France banned them for students under 15 in 2018. South Korea passed legislation last August requiring students to surrender devices to teachers for the entire school day. Hungary made schools smartphone-free in September 2024. The global direction is unmistakable. Japan, still relying on voluntary guidelines and ministerial working groups, has yet to follow.

Research consistently shows that limiting smartphone use in schools improves learning, concentration and mental health. But these policies share a structural blind spot: They work only while students are inside institutional walls. When the bell rings, the policy ends, phones come out and the environment that shaped the behavior resumes unchanged. Policymakers have built a global consensus around the easier half of the problem.

The harder half exists at home, on public transport and on the street. A small city in Aichi Prefecture has now produced data that makes that gap visible.

When Toyoake Mayor Masafumi Kouki proposed including adults in his city’s ordinance, his staff pushed back. Why extend the policy beyond children? Most countries addressing the issue focus on minors. Australia has moved to restrict social media for those under 16. France banned phones in schools. The original target in the Japanese city, officials agreed, should be children.

Kouki disagreed. “Children watch adults,” he said. “They judge whether their behavior is acceptable by what they see.” If adults are constantly on their phones, children will not accept being told to put theirs down.

The ordinance, passed in September 2025, is the first of its kind in Japan. It sets a guideline of two hours of daily leisure screen time and applies to all residents, regardless of age.

Six months later, city survey data suggested he was right.

Of 4,313 student respondents, 65% of middle schoolers reported more than two hours of daily leisure screen use. Nearly half — 46% — slept seven hours or less per night. About four in 10 said smartphone use caused them to go to bed later.

Those figures are striking. But the most important finding lies elsewhere.

Children who exceeded two hours of daily screen time tended to have parents with similarly high usage. The relationship held across age groups. Yet only 10.1% of households had rules governing screen use for both parents and children. In nearly 90% of homes where screen time was a concern, any rules applied only to the child.

This is not unique to Toyoake. It reflects a broader gap in screen-time policy across democratic societies.

The political logic is straightforward. Regulating adult behavior is legally complex, culturally sensitive and politically risky. Protecting children, by contrast, draws broad support. Governments restrict minors’ access to social media, ban phones in classrooms and impose age limits on content while largely leaving adult behavior untouched.

But policies that target only children leave a significant hole. Without addressing both ends of the age spectrum, efforts to reduce screen time are incomplete.

The issue has been framed as “children and screens.” A more accurate description is “families and screens.” That distinction matters. The current framing produces solutions that work only in controlled settings — schools, libraries and structured programs — where adult authority can be enforced.

Toyoake’s data highlights the gap. Households where children used screens for less than two hours a day were also households where rules applied to the entire family. The correlation does not prove causation. But it raises a different question for policymakers: not just how to regulate children’s behavior but how to change the home environment that shapes it.

Kouki’s approach was deliberately nonpunitive. The ordinance has no enforcement mechanism. He described it as a “philosophy ordinance” designed to name the problem and encourage discussion.

He did not expect immediate behavioral change. After the ordinance passed, he visited schools and asked students whether they had reduced their screen time. The answer was uniformly no. He was not surprised. “Creating awareness is the first step,” he said. “We cannot monitor anyone. But if every child knows the city has said this matters, that is already something.”

There are early signs of movement. About 24.5% of respondents said the ordinance made them more aware of their screen habits. Roughly one in five households reported having a family conversation about screen use that had not occurred before.

That suggests the primary value of such policies may not be compliance, but permission — permission to talk. Many parents already recognize they use their phones too much around their children. But without a shared social norm, that awareness often remains private and unaddressed. A public policy, even a symbolic one, names the issue and moves it into the open.

The political challenge is clear. Naming problems that involve adults requires more risk than focusing on children. Kouki anticipated criticism. More than 300 messages were sent to city hall after the vote and online reaction was intense. He considered that necessary. “You need the controversy to get the discussion,” he said. “Without it, nothing moves.”

So far, no national policy response has followed. No other municipality has formally adopted a similar ordinance. Other mayors have offered private praise while declining to pursue the same approach.

That underscores the broader significance of the Toyoake experiment. It shows that policies including adults can produce stronger household engagement than child-only measures. It also reveals the cost: political backlash and limited institutional support.

Japan is likely to face increasing pressure to adopt stricter rules on smartphone use in schools, as many other countries already have. But Toyoake’s data points to a more difficult question — one that extends beyond Japan.

What happens after school?

Policies that focus only on children assume their behavior can be separated from the home environment. The evidence suggests otherwise. The most significant gap in regulation may not be in classrooms but at the dinner table — where most families treat screen use as a children’s issue and where children, watching their parents, learn that it is not.

© The Japan Times