Catchphrase of popular pink character, usually used as a greeting or expression of joy. Equivalent of “nyanpasu” in non non biyori or “selemat pagi” in nichijou, being odd vocalizations that are used by happy-go-lucky characters as a greeting. Note that unlike “nyanpasu” or “wonderhoy”, nichijou’s “selemat pagi” actually means something in real life(being good morning in Indonesian).
People parrot the saying because Emu’s enthusiasm is infectious(wear a mask when interacting with the infected).