By today's standards in any Western country, this poster would be considered racist. But it's interesting how Japan while being an advanced economy has failed to keep up with modern concepts of racism, xenophobia and political correctness. Probably due to the insular nature of the Japanese society and the fact that their nation is still very homogeneous (second only to Korea).
Still, this poster states the truth. Even in Singapore it's always the Indian kids of expat parents who're running around and creating a nuisance in public places because their parents simply allow and condone such behaviour.