In general, the student discount coupon can be used only once per individual.
For example, if you used it in the 1st year at a 4-year educational institution, you can use it for 3 years, but you cannot use it in the 4th year.
However, this restriction does not necessarily apply if you advanced to a higher level of education. If you want to use the student discount again after advancing to a higher level of education once the period of use expired, apply for the student discount again.

Please note that if the student discount coupon expires without being used, it cannot be reissued or its usage period extended, even if you reapply.

Click here to apply for the student discount.
https://www.live2d.jp/student-discount/