Japanese use different words for members of their own family and for members of someone else's family.

There are several different levels indicating politeness or  closeness. For example when talking to or about your own older sister within the family you may use 'oneechan' or even the shorter 'neechan'. And when talking about the same sister with a neighbor lady, you would use 'ane'. And you wouldn't use 'ani' and 'ane' for your own siblings when talking within the family.

• Maki: oneesan wa manga ga suki desu yo ne?
• Taro: ane wa kirai desu kedo, ani wa daisuki desu yo.

• Maki: Your sister loves manga doesn't she?
• Taro: She hates manga, but my brother loves it.

Table of Words for Family Members  

Casual Words

In the family there may be other, more casual ways to call family members. Here are some examples:

• Mother: kaasan, okan
  
• Father: tousan, oton
  
• Older sister: neechan, oneechan
• Older brother: niichan, oniichan
• Grandfather: jiji
• Grandmother: baaba 

Also (young) men may call their wife (うちの) 奥さん "uchi no okusan" when talking with his friends.

Relation by Marriage

The adjective giri no means related by marriage:

義理の息子
giri no musuko  
son-in-law

Prefix

The 御 and お are used when you are speaking of someone elses family in order to show respect and honor, but are not used when speaking of your own family because this seems boastful and can be rude.