Koru are symbolic of life unfolding and represent the unfurling fronds of ferns and similar plants. So it is seen as a sign of 'new growth' of 'new otential' and like the phoenix that rises from the ashes, a sign of the continuity of life in this contingent world, thus the term 'life unfolding'. The entwined koru are the devoted lovers whose love is new and continually growing.
"e te tau, you are entwined with me ... I begin and you complete"