I signed up for a Japanese class. Can I ask for a refund after a class?

This will be discussed with the training institution you reported.

Generally speaking, in this case, training institutions should not agree to refund.

As far as my personal experience is concerned, the Japanese training institution I attended (Wuhan Heisei Japanese) is also non-refundable, but students can resell their courses to other students who want to learn Japanese, as long as they communicate with the training institution and explain. Of course, the specific situation depends on your training institution.