Medical treatment costs
If you need medical care while in Japan, your insurance can cover the costs of treatment.
Cancellation cover
If your flights or other connecting travel gets cancelled, you may be able to claim compensation.
Theft, damage or loss
Most insurance providers will cover you for lost or stolen baggage. You might need to buy gadget cover for more expensive electronic items though.
Emergency repatriation
This can cover the cost of travelling home in an emergency. The long flight time to Japan can mean that flights are incredibly costly if you're not covered.
Travel disruption
This could be because of strikes or adverse weather that causes disruption to your travel plans.