There's an announcement about it at the H!P fanclub, including Koharu's comment (my translation below):
Since graduating from Morning Musume, I've thought a lot about my future.
As I've been hearing from a lot of people that I should try modeling or acting, I've started to think about doing something related to "food and health," which I've studied a lot since I was little and wanted to be like a model.
Of course I still want to work hard at trying things like modeling and singing, but I would like to do work relating to my interest in "food" and "health."
I want to communicate with my fans in various ways, so please continue to support me!
I'll be starting an ameba blog on 4/26. Please check it out!!
Kusumi Koharu
Uh...food and health? So I guess essentially she's going to be like every other OG. She'll probably put out a random single here and there and maybe to some photoshoots for UTB and spend most of her time blogging about food and health.