The higher-ranked of the two largest political units on Rapa Nui was the Ko Tu'u Aro Ko Te Mata Nui. This literally translates as The Mast/Pillar/Post [standing] Before the Greater Tribes.

Toko te rangi, or Sky Propper, is named by Métraux in his corrected Miru genealogy as the thirteenth king of Easter Island and as one of the lineages or subgroups of the Miru. Although we have no record of the Sky Propper legend on Rapa Nui, other Polynesian legends of the Sky Propper are widely known, and they are formative elements in the basic cosmogenic theory of Polyesian beleif.

Sky (rangi) and Earth (papa) lay in primal embrace, and in the cramped, dark space between them procreated and gave birth to the gods such as Tane, Rongo and Tu. Just as children fought sleep in the stifling darkness of a hare paenga, the gods grew restless between their parents and longed for light and air. The herculean achievement of forcing Sky to separate from Earth was variously peformed by Tane in New Zealand and the Society Islands, by Tonofiti in the Marquesas and by Ru (Tu) in Cook Islands. 

After the sky was raised high above the earth, props or poles were erected between them and light entered, dispelling the darkness and bringing renewed life. One detail which is iconographically of interest is whether the god responsible for separating Earth and Sky did so by raising the Sky with his upraised arms and hands, as in Tahiti and elsewhere, or with his feet as in New Zealand.

The actual props, pillars or posts which separated the sky and earth are called toko in New Zealand, to'o in the Marquesas Islands and pou in Tahiti. In Rapanui tuu and pou are known, with pou meaning column, pillar or post of either stone or wood. Sometimes the word is applied to a natural rock formation with postlike qualities which serves as an orientation point.

The star Sirius is called Te Pou in Rapanui and functions in the same way. 

One monolithic basalt statue is called Pou Hakanononga, a somewhat obscure and probably late name thought to mean that the statue served to mark an offshore tuna fishing site.

The Rapanui word tokotoko means pole or staff. Sacred ceremonial staves, such as the ua on Rapa Nui, were called toko in Polynesia. 

Based upon the fact that toko in New Zealand also means 'rays of light', it has been suggested that the original props which separated and held apart Sky and Earth were conceived of as shafts of dawn sunlight. 

In most Polynesian languages the human and animate classifier is toko-, suggesting a congruence of semantic and symbolic meaning between anthropomorphic form and pole or post. Tane as First Man and the embodiment of sunlight thus becomes, in the form of a carved human male figure, the probable inspiration for the moai as sacred prop between Sky and Earth.

The moai as Sky Propper would have elevated Sky and held it separate from Earth, balancing it only upon his sacred head. This action allowed the light to enter the world and made the land fertile.

Increasing the height of the statues, as the Rapa Nui clearly did over time, would symbolically increase the space between Sky and Earth, ensuring increased fertility and the greater production of food. The proliferating image, consciously or unconsciously, must have visually (and reassuringly) filled the dangerously empty horizon between sea and land, just as the trees they were so inexorably felling once had.