Metoro's word viri has a basic meaning of 'going around' or similar ('ball', 'roll up' etc).

1. The Chinese (and Japanes) sign for 5 is said to be based on a picture of a thread-reel:

(Ref.: Henshall)

The year can be regarded as having 5 parts - the regular 4 quarters and an extra 'dark' period outside the calendar before next year can begin. The last period can then be associated with the fingers on a hand (rima).

On Easter Island, where the major structure of the year probably was two half-years, two 'thread-reels' were presumably needed, one at the end of the 1st half-year and another at the end of the 2nd half year.

When a thread is rolled up around an object it disappears. It is made invisible and therefore 'detronised'. Same thing with periods of time, they must be made to disappear.

When Bishop Jaussen on Tahiti received his first rongorongo tablet (Échancrée) it had been made harmless by being wrapped in a '16m-long skein of braided human hair'. Probably it was hair from women, whose hair is extra potent. (Cfr how Maui used the tresses of his sister Hina to make a rope whose mana could not be destroyed by Ra.)