Yamashita Tomohisa talked about NEWS during a radio show “Sound Tripper!” (InterFM) on 18th December 2015.
The theme for this week was “Year 2011”.
For Yamashita, it was the year he left NEWS to go solo.
Reflecting on that year, he confessed “At that time i had to do what i was thinking. I didn’t want to continue, I was self-centered. Indeed i was still childish then. When i turned solo, i started to realise the importance of having a group and comrades.”
He revealed that he continues to be connected with NEWS members in some ways.
“Recently i met Masuda Takahisa at a TV station and talked about going for drinks. Koyama Keiichiro also told me that he changed numbers.”
Seeing them working hard, he feels like he has to do the same.
Bittersweet feelings
AllThingsJpop 
sounds like regret….
I don’t think he’s particularly successful since he left.
I don’t think he’s regretting since it makes him learn how important the NEWS members and NEWS fan is.
If he didn’t decide to go solo, he might not learn about this point and become who he is today.
For his solo career, he might be struggled because of the hate, but I think what more important than success is to be able to stay in the showbiz for a long time, and he was already success when he was young. I think another peak moment in showbiz is difficult to happen for everyone in entertainment industry.
Sorry for long answer^^
he got a fairly successful solo music career as expected from a male soloist selling around 100k copies of his single/album.
and he managed to secure another 3 fujitv getsu9 dramas (with good ratings) post NEWS so he’s doing very well alone.