I'm a librarian who loves anime, manga, and reading a wide variety of genres.
I wish I knew who had done the cover art for this one. It reminds me of Kate Beaton's stuff.
After several Google searches...
Success! The art was created by Noelle Stevenson, who also created the cover art for Rainbow Rowell's Fangirl.
Can I just say, I would love it if cover artists were searchable everywhere you can buy books? Yes, I know you shouldn't judge books by their covers, but I can't help it, I do. And sometimes I just want to read stuff featuring cover art by certain artists.