nope its in the north island, and the person lied to you, its Mount Taranaki. Well thats the Maori name and what it is most commonly known as in New Zealand.
They should come to the South Island and hike Mount Aoraki, also known as Mount cook which is our highest peak in NZ.
Wikipeadia info on Taranaki
http://en.wikipedia.org/wiki/Mount_Taranaki
Was not aware it was used for the back drop as mt Fuji in the last samurai, thats pretty cool.