Hawaiian Greetings

Traditional Hawaiians would greet people by pressing their foreheads together and breathing through their noses. Breathing through your nose is considered the purest way to take a breath. Riley’s grandpa would greet him and his siblings and cousins with this traditional greeting. He would bend down and place his forehead against each of their foreheads then take one deep breath through his nose and exhale. It was an intimate way of greeting people to show that you cared for the person and respected him or her beyond words.
In addition, kids were to greet elders or other parents who were outside their family as Uncle or Auntie instead of Mr. or Mrs. It was very disrespectful to call someone by the title of Mr. or Mrs. Riley, for example, would walk into a cookie shop and greet the shop owner as Auntie May, even though she had no family relationship to him.
The use of Auntie and Uncle to address elders most likely was used to represent that all Hawaiians are family, despite of what blood you have. It makes sense with Hawaiian culture to treat everyone who lived on the islands as family because the islands collectively represented one giant family.