NZART reports that the New Zealand Administration (MBIE) and Japanese Administration (MIC) have signed an agreement formalising reciprocal licensing between the two countries.

Under the agreement:

the NZ General Amateur Operators Certificate will be recognised as equivalent to the Japanese First Class Radio Operator’s qualification and
a NZ Amateur will be will be permitted by MIC to establish and operate a station as an amateur radio operator in Japan.

Similarly

the holder of a Japanese First or Second Class Radio Operator’s qualification visiting New Zealand may operate for up to 90 days using their Japanese assigned call sign, with the addition of the ZL prefix.
the Japanese First and Second Class (but not Third and Fourth Class) Radio Operator’s qualification will be recognised as equivalent to the NZ General Amateur Operators Certificate; and

NZART Website - http://www.nzart.org.nz