Those flowers are from the Fuji TV staff.
Kuu says this was her last work day as a 37 year old.
FNS is by Fuji TV, so she probably prerecorded her performance this time.
The HMV in Narita renewed the big Kuu display again and made a big panel with birthday messages from fans (and a book out of it they gonna give her).
Fans were able to leave handwritten messages in the store as well as on Twitter, it's 1,000 altogether.
https://mobile.twitter.com/HMV_Narit...20095773069312