That means "hello" in Japanese, and I learned it from this 1990 book, Japanese for All Occasions by Anne Kaneko:
I don't speak Japanese (nor do I fluently speak Cantonese, even though I'm Chinese), but it's always handy to know new words in new languages.
So here are some practical Japanese-to-English examples (with corresponding page numbers) that are useful for all occasions:
p.71 - Kono chiizu o kinō kattan' desu ga, furukute taberarenain' desu."I bought this cheese yesterday but it's so old that we can't eat it."
p.116 - Moshi-moshi. Sanbyaku-san gō-shitsu desu ga, rāmen o motte kite kudasai."Hello? This is room 303. Can you bring a bowl of needles." *
* I misread "noodles" as "needles". Please do not eat!
p.146 - Piinattsu ga nodo ni tsumatte iru."He's got a peanut stuck in his throat."
p.209 - Honjitsu wa, watashi no tsutanai hanashi o o-kiki itadaki, makoto ni arigatō gozaimashita."Thank you for listening to my poorly delivered speech."
p.21 - Dewa mata."See you./Bye!"