Kahui only made his international debut in June of this year but he has impressed with his attacking abilities and versatility, having been employed on the wing as well as in midfield.
The 23-year-old was a try scorer in his first appearance All Black against England and earned the man-of-the-match award in his most-recent Test start against Scotland.
The Waikato player is the only change to Graham Henry's starting XV from the 22-3 win over Ireland after prop Tony Woodcock was found guilty of foul play but escaped any further punishment following his yellow card in Dublin.
Fellow prop John Afoa could yet come in for Neemia Tialata who is being given more time to prove his fitness for Saturday's match.
Replacement hooker Corey Flynn joins early absentee Andrew Hore in missing the remainder of the tour after suffering a broken left arm at Croke Park. His place on the bench against Wales will be taken by Hikawera Elliott.
Henry and his fellow coaches will make a decision on whether to summon a tour replacement for the match with England a week on Saturday after this weekend's game at the Millennium Stadium.
New Zealand: Mils Muliaina; Joe Rokocoko, Richard Kahui, Ma'a Nonu, Sitiveni Sivivatu; Dan Carter, Jimmy Cowan; Tony Woodcock, Keven Mealamu, Neemia Tialata/John Afoa, Brad Thorn, Ali Williams, Jerome Kaino, Richie McCaw (capt), Rodney So'oialo
Replacements: Hikawera Elliot, TBC, Anthony Boric, Kieran Read, Piri Weepu, Stephen Donald, Isaia Toeava