This image is of (spoiler warning in links) Solne and Koma from the 2005 visual novel/eroge Ouka by Carriere. As far as I know, there's no anime or manga adaptation. They also appear in the original game Shinkirou (which Ouka was an expanded remake of), but the character design in the image matches Ouka's. As you can probably guess from the image, Solne is one of the main characters in the game, while Koma is the cute mascot animal (she's not actually a cat).
The plot from vndb:
The last descendant of a line of mystical protectors, Yuuya Furusaka has received the twin blessing of Life and Death, and now his touch has the power to save lifes or destroy them, although at the price of, respectively, his own life or his own soul.
But maybe the key for his salvation is hidden in one of the girls around him...
In case you're unsure it's the same character, if you look at the full version of this image, you can see the Carriere logo in the lower left corner. Modified versions of this image have been used for some of their merchandise, e.g. this ZIPPO lighter.