Going to get the two soloist out of the way, even though I do actually follow one of them.
I still like Nakayama Yuma though I am still not certain if a solo career is right for him. But Johnny's seems set on that now that they have dumped the NYC group. I have enjoyed his releases so far, though Missing Piece is the stronger single compared with High Five, IMHO. But I still look forward to whatever his next music release will be.
He is one of those Johnny's that I do like to follow when it comes to dramas. Even though I have not cared for all the ones he has done I do think he is one of the more talented actors with Johnny's. I would like to see him play some roles with larger ranges than he has as I believe he is up for the challenge.
Either way Yuma is staying on my radar, and since he does not release things very frequently I can afford to do so.
Yamashita Tomohisa lost me around the time he released his first solo album. I liked his singles before that but the album did not stand out much to me. Then he switched music styles to go with his solo career and I cared even less for that. And the whole Ero-pi thing just feels silly and makes him look like he is just trying way too hard for his persona.
Yamapi was not a favorite of mine when he was in NEWS though so it probably is no surprise that I have come to not follow him now that he is solo. At this point any grudge I may have held against him is gone and nothing I have heard about his solo career has made me interested in him.