Google keyword "air china 24 hour cancellation"
想當然了吧。請看air china的細節。東京到上海的機票不受美國規則管轄。
https://www.airchina.us/US/GB/faq/
In accordance with U.S. regulations, tickets purchased on Air China's U.S. website may be cancelled within 24 hours of purchase if the reservation is made more than seven days in advance of departure, and the ticket must include transportation from/to the U.S. To cancel a ticket, submit a cancellation request on Air China's U.S. website, and then call Air China's U.S. hotline on +1-800-882-8122.
