Please tell me how to handle flight tickets (transfers/refunds) in the event of flight cancellation or significant delay.

You will receive an email notifying you of flight cancellations or significant delays.
After clicking "Manage My Booking" on the top right of the AirJapan website, please enter your flight reservation number and your last name.
You will be redirected to the "Reservation Confirmation" page where you can check or change the scheduled departure time of your reserved flight, or perform refund procedures.

• If you wish to transfer
  Click the "Change Flight" button on the "Reservation Confirmation" screen above on the AirJapan website and change your schedule to a date with available seats within 14 days before or after the departure date of your reserved flight.
  After making changes, please obtain the new itinerary from the same screen.
• If you would like a refund
  We will accept refunds without charge.
  Please click the "Cancel Reservation" button on the "Reservation Confirmation" screen above on the AirJapan website to issue a refund.

For other details, please check