CZ 8309 then TW 250 at Narita
Shanghai → Tokyo → Seoul
Timetable, Tokyo time
13:15CZ 8309 from Shanghai at the gate
08:55TW 250 to Seoul leaves the gate
19 h 40 apart on the timetable, overnight
TW 250 leaves 19 h 40 after CZ 8309 arrives on the timetable: more than half a day, so not a connection we count.