Found both Fiji Airways and Air New Zealand have great prices at present to Japan. Fiji Airways tends to be cheaper, but the Air NZ ones are sometimes direct (if not codeshared through Taipei).
Singapore Airlines also shows up occasionally, so feel free to play around with dates. I've put in some of the best prices below.
Don't forget to look at hotels too, we're seeing them up to 60% off!
Auckland to Tokyo
Dates: 01 February 2023 - 30 November 2023
Cheapest is $1289
Wellington to Tokyo
Dates: 01 February 2023 - 30 November 2023
Cheapest is $1294
Christchurch to Tokyo
Dates: 01 February 2023 - 30 November 2023
Cheapest is $1299
Does anyone know how much and the best way to visit Korea from Japan? My wife want's to visit both so I'm wondering if this deal sets it up good?