Kampang is proud of its toilets. Spotless, and surrounded by flowering tropical plants, they have won national awards for cleanliness.

But there is something else about them too. Between the girls' toilet and the boys', there is one signposted with a half-man, half-woman figure in blue and red.

The headteacher, Sitisak Sumontha, estimates that in any year between 10% and 20% of his boys consider themselves to be transgender - boys who would rather be girls.

"They used to be teased every time they used the boys' toilets," he said, "so they started using the girls' toilets instead. But that made the girls feel uncomfortable. It made these boys unhappy, and started to affect their work."

Tolerance, said Suttirat, is not the same thing as acceptance.