Kuu (and Kenji) are taking part in music producer UTA's song project (the composer she already tagged in the FNS post with AI some days ago).
He's making a song with everybody staying at home - literally, cause anybody can send him a recording and proposals through his Instagram.
Kuu and Kenji provided melody parts, lyrics and vocals themselves (Kuu posted samples in her stories and Kenji had an Insta live with him yesterday about it).
I'm really happy right now that Kuu fell in love with and married a singer-songwriter/composer herself, so they have a studio at home and work on stuff, hahaha.
Looking forward to the final songs.
On another note It's all Love (132k) already surpassed BUT (129k) in views on youtube.
This always was a popular song among her Japanese fans, partly e.g. because of the lyrics being like a discussion about love between the two sisters.