With Asiana 24 hour cancellations are covered under a policy. It works in the following manner:

You can discontinue reservations online.
Approach the branch office of Asiana in case purchases were made through it.
On the same day of reserving flights, you can reverse them.
Prior to 24-hour revocations, ensure that 7 days are left prior to take-off.

What is Asiana Airlines Refund Policy?
Asiana refund policy is implemented by this airline. It works via some rules. 

These rules vary depending on the location of purchasing tickets.
For Award, promotional, or group tickets, contact Asiana to know the terms.
You can receive baggage charges back when canceling flights before their departure.