Pretty slick. They likely won't be getting sued for that little bit of plaigerism. If it were just the hairstyle I'd say it was a coincidence, but the face looks like the exact same style. The body looks pretty familiar too, but not Raika's. I'll have to go back through the gallery to check, but I'm pretty sure that's Raika's recoloured head pasted on Mika's body.
I guess if you want to shamelessly rip off artwork, getting it from a defunct japanese H-Game company is the way to go.
Edit: Yep,
this is the pic of Mika they used. To their credit it's less of a cut and paste job and more of a tracing job.
This would be the Raika head they used.