To check for yourself whether the “Sign up to Microsoft 365” required for watching Stream videos etc. is done correctly, please try signing in from https://www.office.com/.
If you have signed up, you can also sign in.

Also, if a user who has already signed up tries to sign up again, a message such as “This account has already been registered” will be displayed, so you can confirm that you have signed up with this method as well.

The following is an example of the home screen after signing in.
[For students (@s.tsukuba.ac.jp)]
#Theme is left at its default setting.

[For faculty, staff, and students (@u.tsukuba.ac.jp and @un.tsukuba.ac.jp)]
#Theme is customized.

If you receive a message such as “This account has already been registered” and cannot sign up for an account that you do not remember signing up for, please go to Inquiry Form, select “EES(including Microsoft 365, Teams, Stream, etc.)” as the inquiry type and send us your inquiry.