Go to https://login.microsoftonline.com/, select “Select Account” > “Forgot Password” on the “Enter Password” screen, and follow the instructions to reset your password.

Logging into the Office 365 Portal requires a new password, which is defined by the user upon signing up for EES advantages instead of the unified verification password.

Apparently, you can receive some charge-free services from Microsoft by creating a Microsoft ID using your personal email address. That is not related to this service of ours. We do not recommend using your @s, @u or @un email address to create your Microsoft ID. That could cause a problem when you receive services from the University of Tsukuba.

You need to sign up (register) using your “@u.tsukuba.ac.jp” or “@un.tsukuba.ac.jp” email address, which is provided by the University of Tsukuba. If your email address is not accepted, make sure that you have made no typos. Please note that email address ending with “@s.tsukuba.ac.jp” cannot be accepted.
We request students enroll in 2017 or later to read the following website carefully:
Microsoft Office (for private use)

There is no problem to continue using the Office already installed. In order to install Office provided by the University of Tsukuba, you need to uninstall the existing Office. These tasks must be done at your own risk, and the University of Tsukuba does not support it.
If you use Office provided by Tsukuba University, you can always use the latest version. In this sense, decide for yourself whether to use the Office already possessed or the Office provided by the University of Tsukuba.
If the Office you already have is no longer supported, please use the Office provided by the University of Tsukuba.

Do it by

1. Sign-in yourself in https://myaccount.microsoft.com/
2. Click the “My sign-ins” in the left-edge menu
3. Your recent active sign-in history is displayed

For detail, also refers to Microsoft’s newest document. (eg. search keywords “Microsoft365 recent activity” and read the Microsoft Support in that page.)
If you also want to change your password, please read this QA, ignoring the URL told in that document.

Do it by　

1. Sign-in yourself in https://myaccount.microsoft.com/
2. Click the “Password” in the left-edge menu .
   (If you have set to received confirmation code in SMS or e-mail, do as instructed)
3. Change your password as instructed.