In Japanese, the way to say "daddy" is "papa" (パパ). Although it is a loanword from English, it is regularly used in Japanese to refer to one's father. Other terms for "daddy" in Japanese include "otou-san" (お父さん), which is a more formal way of saying "father," and "chichi" (ちち or 父) which is used mainly by children. Finally, "tousan" (とうさん) is used mainly by young men and is a more casual version of "otou-san".
