I won't claim to be 100% sure it's Nemu (the facial expression made me think of Kana at first), but her face matches up pretty well to his next drawing (post #451148) which is definitely Nemu.

Well, the fact that "Kana" means "River Fish" plus the way the hair is parted makes me feel like it's more Kana than Nemu. Nemu's hair is also a lot longer, more wavy than Kana's straight hair, and the facial expression is definitely Kana.

Oh, the flatter breasts too. Kana is rather flat-chested as opposed to Nemu, who this guy seems to draw rather well endowed.

And the eyes aren't closed enough. They're wider than Nemu's eyes, and less sleepy-looking.