Are there nonstop flights from Tokyo (NRT) to Nankoku (KCZ)?

Yes. Jetstar Japan fly this route. Flight time is about 1h 17m.

What is the fastest connection from Tokyo (NRT) to Nankoku (KCZ)?

via Nagoya ≈ 1h 47m, via Osaka ≈ 1h 47m, via Osaka ≈ 1h 48m (estimated flying time, excluding layovers).

from 12,000 ANA miles (economy, one way, based on the published award charts).

Narita International Airport (NRT) to Kochi Ryoma Airport (KCZ)・662 km

Nonstop flights available (1 airline). Flight time about 1h 17m. Nonstop return flights also operate.

With milesANA 12,000 miles+ (via ITM)Economy, one way, estimate. Tap a connection for miles by cabin.

4 one-stop options, sorted by estimated flying time. Tap one to see the airlines on each leg and booking links.

Times are estimated from distance. Check schedules, frequency and availability with the airline or a booking site.