So Johnny's net updated with new videos mostly for those who are in dramas this current season which had me surprised to see that B.I. Shadow was among then. It turns out that Nakajima Kento is in a drama this season, Taisetsu na Koto wa Subete Oshietekureta, which stars Toda Erika and Miura Haruma.
From what I can glean from the cast list and what I know of the drama's plot he's probably playing a student for one of the main characters as they're both teachers, IIRC. I may be updating this a bit later once I've watched at least the first episode.
But either case I'm rather happy he's gotten another acting role as I think he's one of the more promising Juniors at the moment.
Taisetsu na Koto wa Subete Oshietekureta OHP staff/cast page. (Japanese)