K4 550 then BX 224 at Narita
Chicago → Tokyo → Seoul
Timetable, Tokyo time
11:59K4 550 from Chicago at the gate
11:10BX 224 to Seoul leaves the gate
23 h 11 apart on the timetable, overnight
BX 224 leaves 23 h 11 after K4 550 arrives on the timetable: more than half a day, so not a connection we count.