AA 2461 then K4 556 at O'Hare
Boston → Chicago → Tokyo Narita
Timetable, Chicago time
20:12AA 2461 from Boston at the gate
09:05K4 556 to Tokyo Narita leaves the gate
12 h 53 apart on the timetable, overnight
K4 556 leaves 12 h 53 after AA 2461 arrives on the timetable: more than half a day, so not a connection we count.