Answer by Japanese teacher
The number “one” is “いち ichi” in Japanese but there are many ways of saying “one” in Japanese, depending on the object that you are attaching the number to. In this case, if you want to say “one person”, the word is hitori. If a waiter asks how many of you while you are entering the restaurant, you can say hitori desu.
If you want to order one item from a menu, you can “一つお願(ねが)いします。Hitotsu onegaishimasu.” Hitotsu is “one (item)” and onegaishimasu is “please”.
If you are interested to learn more about how to say “one” for different items, be sure to check out our articles.