AramaJapan.com - Ayumi Hamasaki to Retire
*insert Philip J. Fry meme pic with the caption "Not sure if real news, or if April Fools joke"*
Long story short, Ayu performed on the 2017.03.31 episode of Music Station. The article here implies that her performance was pretty bad, and that there was a lot of negative comments on social media. As a result, Ayu apparently decided to retire/quit from the entertainment industry.
Now, as of this post, apparently this would have been posted 2 or 3 days ago (i.e. a day or 2 after the performance, which would possibly mean that it was posted on April 1st). I haven't watched MSta in forever so I have no idea how her performance actually was. Personally, I'm betting it's AramaJapan.com's prank for April Fools Day.