It is possible that the email was classified as spam or that there is a mistake in the email address entered during the application process. Please check your spam folder first. If the email is not in your spam folder, please double-check that you have entered the correct email address and try applying again.
If the issue persists, please note that if you are using an email address provided by a mobile carrier (such as example@softbank.ne.jp), it may be blocked by the email server. In this case, please add the domains "getsugaku-panda.jp" and "kaihipay.jp" to your email's whitelist or try registering with a different email address.