Family

English	Japanese
(polite) family	gokazoku
family	kazoku
(polite) mother	okaasan
mother	haha
(polite) father	otousan
father	chichi
(polite) older sister	oneesan
older sister	ane
(polite) older brother	oniisan
older brother	ani
(polite) younger sister	imoutosan
younger sister	imouto
(polite) younger brother	otoutosan
younger brother	otouto
daughter	musume
son	musuko
aunt	obasan
uncle	ojisan
niece	meisan
nephew	oisan
cousin	itoko
grandmother	obaasan
grandfather	ojiisan
granchild	mago
siblings	kyoudai

Notice that the first set of words has both a polite and a regular form. (The polite form is marked with (polite).) The polite form should be used when referring to others' families or when speaking to people in your own family. The other form should be used when referring to your family to members outside your family.