Perhaps a response to herbicide, as several unrelated shrubs across the playground were showing similar leaf curl symptoms. I had a good look inside the folds on the kawakawa leaves and could see no invertebrates with my naked eye.
Piperales is a botanical name for an order of flowering plants. It necessarily includes the family Piperaceae but otherwise has been treated variously over time. Well-known plants which may be included in this order include black pepper, kava, lizard's tail, birthwort, and wild ginger.