How has the relationship between Ishi and Tushi changed since they first came to Wowunupo?

Ishi and Tushi know that their relationship can never be romantic, but they have become companions. Ishi admires Tushi's beauty and enjoys her company. They are partners in providing for the needs of their village and they work well together. In turn, Tushi relies on Ishi's company and continues to look up to him. Their relationship has become a marriage in all but one very important way.