June 17th is Father's Day, which is known as, "Chichi no hi (父の日)" in Japanese. There are two terms that are mainly used for "father" in Japanese: "chichi (父)" and "otousan (お父さん)". "Chichi" is used when referring your own father, and "otousan" is used when referring somebody else's father. However, "otousan" can be used when addressing your own father. As for mother, the terms, "haha" and "okaasan" are used, and the same rules apply. Here are some examples.