As per $(you need an account to see links)'s first post: Take care of your Ryu in-between 12-12:30 am in your current timezone. You can check to make sure your timezone is up to date (you need an account to see links). @(you need an account to see links) when you visit your edit profile page, is the time listed the same as your actual time zone? (It's next to the ryu stars.)
Also, yes, your ryu will need to be 5/5 stars to stay in the same branch.