This looks like Misa Amane, and maybe the K on her hat stands for Kira?

No, this isn't Misa. This cg from an original h-game.

What game?

Apparently it's called: Here goes the manager! Summer 2008. It's about a female baseball manager who does anything to "encourage" the team. Here's the dlsite page: http://eng.dlsite.com/work/=/product_id/RE037836.html.