The anime tie-in is officially announced now.
http://rhythmzone.net/koda/news/detail.php?id=1062969
http://bclover.jp/music/
The mobile phone game hasn't a release date yet, but it is confirmed for 2018 as well as Kuu's tie-in with it.
Kuu also made social media posts about it with a look from one of her new PVs.
It is interesting, that Haircut and Watch Out are getting the PVs and not the song with the big tie-in.
Guess that's because the two songs fit to the album concept and Guess Who Is Back doesn't.
Kuu describes Guess Who Is Back in a comment on her Insta post as a "call and response"-song, a powerful song.
She wants everyone to yell "Hey guess who is back!!!" with it.