If I cancel my ticket, can I still use my insurance?

Not available. In addition, regardless of whether you are on the outbound or inbound journey, you will need to cancel the insurance for all the members of the overseas travel insurance by yourself. Sorry for your inconvenience, but you can cancel it from the following. If you would like to take out insurance again, please follow the procedure below.
[Departure and arrival in Japan]
Overseas Travel Insurance: https://ssp.chubbtravelinsurance.com/ctijp
Travel Cancellation Insurance: https://ssp.chubbtravelinsurance.com/ctijp
[Departure and arrival in Thailand]
https://ssp.chubbtravelinsurance.com/zipairth
[Those who wish to join again]
https://www.chubbtravelinsurance.jp/zipair