"He was larger than life and lived life totally to the full. He had the greatest sense of humour and was the life and soul of the party.
"He always thought about other people.
"Not that it's any consolation, but he died doing what he loved."
Kerr posted a photo of himself in the snow to Facebook just hours before the tragedy.
He leaves behind his wife Yuka and their 4-year-old son Rui who Lee said are totally devastated.
Lee said her nephew "fell in love" with Japan during a working holiday and moved there in about 2007 after which he set up ski-touring business Niseko Xtreme Tours.
"He was very highly regarded for what he did. He was loved right around the world because of his job."
Kerr's sister had just arrived in Japan a few days ago to visit her brother and his family
His mother Linda was travelling to Japan today alongside other family today.
One other person suffered minor chest injuries in the avalanche.
A Givealittle page has been set up by a friend of Cave's since she was three, to raise funds to support his family and bring him home to New Zealand.
Lee said it is not yet confirmed if Kerr's body will be brought back but either way, there will be a memorial service for his family and "strong, strong circle of friends."
A spokesperson for the Ministry of Foreign Affairs and Trade said: "The Ministry is aware of the death of a New Zealander in Hokkaido.
"The New Zealand Embassy in Tokyo has offered consular assistance to the family of the deceased."
