The literal English translation for Ha’a is ‘kind or class’.  The Ha’a is the largest socio-political unit in Tonga.  This is a grouping of related people that can trace their ancestry to a founding or principal hereditary Chief.  The main branching arms of the Ha’a include the Ha’a Ngata - Ha’a Ngata Tupu, Ha’a Ngata Motu’a and the Havea Havea – Ha’a Havea Lahi, Ha’a Havea Si’i.  The head of the Ha’a Havea Lahi is the Hou’eiki Ma’afu of Vaini and Tokomololo. 

There are also Ha’a or classes of people associated mainly with functions or duties they perform specifically for the Chiefly Ha’a.  The Ha’a tufunga are the Ceremonial custodians in charge of ceremony for Kings and Chiefs.  The head of this Ha’a is Lauaki.  Within this class are a specific group called the Nimatapu or Sacred hands.  These are the only people who can touch the deceased Kings and Chiefs.