"To have the taonga back in our hands, I think, is just a fabulous achievement for us, and it's something that will be reminiscent of a time when our people worked the land and mixed with Pakeha -- it was a time of new discovery for them and new discovery for us.
Aratoi Director Alice Hutchison said the "beautiful news" of the item's acquisition came just in time for Waitangi Day this weekend.
The cloak will be housed at Nelson Provincial Museum until it is brought to Aratoi in the coming months.
"We're going to be looking at doing a full karakia with Marama and our iwi in Nelson at the museum, so it's going to be really exciting for us," Ms Hutchison said.
"I met with Marama last month regarding the online sale and we had a good conversation about how it's all panned out and, you know, she really really advocated hard for it."
The cloak was originally bought in Wairarapa in the late 19th Century by an American tourist and had been in the Rochester Historical Society collection until the end of last year, when it was sold on ebay for $163 New Zealand dollars to an Auckland buyer, and was then onsold to a Nelson buyer for $6000.
Ms Hutchison contacted the Rochester Historical Society in America to "check the provenance and check that it was in fact legitimate and that it had a back story".
"I had to check things out first with the Rochester Historical Society and with Gareth Winter because I didn't want to validate any potential internet extortion, but actually it is legitimate," she said.
"Marama had been in contact with the Nelson buyer and she contacted me also and we've been in lengthy conversations about it.
"Because the korowai needs to be in a climate controlled environment, it will be coming here to the museum.
"I'll split the cost with Aratoi, Rangitane, and Kahungunu so it will be joint ownership, but stored here at Aratoi."
Ms Hutchison said she could not disclose how much Aratoi and Wairarapa iwi had bought the korowai back for, but said it was "quite legitimate to pay this amount for it", having found the provenance.
"I think the collector was also very generous because he had had higher offers," she said.