Are there nonstop flights from Nankoku (KCZ) to Singapore (SIN)?

No. The fastest connection is via Taipei, about 6h 35m of total flying time.

What is the fastest connection from Nankoku (KCZ) to Singapore (SIN)?

via Taipei ≈ 6h 35m, via Fukuoka ≈ 6h 40m, via Osaka ≈ 6h 58m (estimated flying time, excluding layovers).

from 13,000 JAL miles, from 15,000 ANA miles (economy, one way, based on the published award charts).

Kochi Ryoma Airport (KCZ) to Singapore Changi Airport (SIN)・4,729 km

No nonstop flights. The fastest connection is via Taipei (TPE), about 6h 35m of flying time (layover not included).

With milesJAL 13,000 miles+ (via HND)ANA 15,000 miles+ (via HND)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

6 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.