Another animated series with belly expansion by poisoned milk

I have seen an asian animated series with belly expansion like Wicked's scenes around 1990s. I'm not sure that animated series is from China or South Korea.

As far as I remember in this episode, Villains stolen a milk truck and they poisoned these milk then 4-6 boys are jocking near this area.

The villains hide in side way and watch these boys. All boys found poisoned milk and drank it. They start jocking again. Afterthat they feel strange in their bodies. Suddenly one boy found his belly enlarge like a ballon and other boys's bellies also bloated. All boys have belly expanion with that poisoned milk.

Anyone know the name of this animated series?