Forgot Password: Use "Forgot Password" on the login page and click the email to reset; if you have not received it, please check the spam box or "Contact Us" on the official website.
How to change password for Google / LINE login: There is no on-site password for third-party login; please add and verify your email address in "My → Account" and then set a password. There are the same instructions at the bottom of the password change pop-up window.
Child/student account cannot log in: Confirm the account and password length; see Login and Account FAQ.
Want to use LINE to log in to your child/student account: Not supported, please use App.