My edits
I rewrote somewhat to avoid a combining of the traditions of different parts of Polynesia. I also tried to change the emphasis in the opening line to Pulotu as 'Polynesian mythology' which gives the mistaken impression that the concept is found all over Polynesia. It is important to maintain the separation of the individual traditions - otherwise we are at risk of rewriting the traditions. The association made with the Māori concepts of Hawaiki and Te Reinga I thought was taking it a little too far - Hawaiki is not always/often conceived of that way by my people. I also took out a reference to 'Purotu' since there was no evidence offered that the word occuring in that form means underworld. I also took out the reference to Pulotu having changed in Tahitian to purotu meaning a girl of marrying age. The word occurs in many Eastern Polynesian languages with the meaning beautiful:

HAW   Puuloku. Comely, tender (Pki)@
MAO   Purotu. Handsome, clear, pleasant (Wms)@
MVA   Porotu. Beauty, handsome person (Bck)@
PEN   Purotu. Beautiful (Rsn)@
PUK   Pulotu. Beautiful (Bge).
RAR   Purotu. Pleasant, pleasing, agreeable (Sve)@
TAH   Purotu. Joli, beau (Mte)@
TUA   Purotu. Slightly handsome, attractive (Stn)@

versus
SAM   @

There is nothing here to suggest that the word changed in Tahitian (or that it is only used of women); nor is there any evidence to suggest which meaning is the older, the eastern Polynesian 'beautiful' or the western Polynesian 'residence of the gods'