Quick note: American, which had dropped its service to Tokyo Haneda during the tourism downturn, is now resuming the flights beginning tomorrow (or, as I’m writing this from Australia, where it’s already tomorrow, they will resume the flights today. Which is tomorrow. But not here. OK, June 1st).
JAL will fly the JFK-Narita route while American will take the JFK-Haneda trip. Flights depart JFK at 655pm, arriving at 1015pm (due to slot restrictions at Haneda, international flights arrive at off hours); then depart at 650am, arriving exhausted for the day ahead at 640am in New York.