UA 824 then KE 552 at Narita
Saipan → Tokyo → Seoul
Timetable, Tokyo time
16:00UA 824 from Saipan at the gate
19:01KE 552 to Seoul leaves the gate
3 h 01 apart on the timetable
The last days
UA 824 and KE 552 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.