NH 8421 then KE 712 at Narita
Chicago → Tokyo → Seoul
Timetable, Tokyo time
18:38NH 8421 from Chicago at the gate
17:10KE 712 to Seoul leaves the gate
22 h 32 apart on the timetable, overnight
KE 712 leaves 22 h 32 after NH 8421 arrives on the timetable: more than half a day, so not a connection we count.