It has been announced that Yamada Ryosuke will be making his solo CD debut on January 9th, 2013 with a single called Mystery Virgin. This song will be the theme song to his upcoming drama special Kindachi Case Files.
Sanspo article (Japanese)
This is actually not too surprising with him getting a solo song to be the theme song of this SP, as all previous Johnny's that have had the lead role have had solo songs for the theme song. So in a way it is in tradition, though I think this is the first time the solo song will be a solo debut.
I know there are definitely fans unhappy about this and I can understand. Yamada does already get a lot of promotion and now getting a solo release when Hey! Say! JUMP have not released a CD for about half a year seems unfair in that regard. Then of course there are those who are probably worried this could lead to him dropping the group to go solo like Yamashita Tomohisa has done.
For me, I plan on being pragmatic about all this. There have been plenty of instances where a member from a group released something solo and it did little to affect the group in the long run. In a way I am a bit hopeful that maybe we could get at least one of his older solos on the single so we just have more solo songs on a CD, something that HSJ has done so little of with their releases. I also feel that Yamada is close enough to the members of the group he would not want to leave it to take on a solo career. He has been with Nakajima Yuto and Chinen Yuri for so long as a Junior, he is known to be friends with Arioka Daiki and Okamoto Keito, so overall he is much closer to his group members than the recent soloist such as Yamapi and Akanishi Jin. And I think that fact will keep him with the group and this solo single will be more of a one off thing than anything else.
Of course I would rather have had a group single, but as a long term HSJ fan I have learned that if you want to stick with this group you need to have low expectations. That way there is a lot less disappoint and many more happy surprises.