No, no, no. Harada didn't do this or any of the art for the Disgaea Light Novels. The artist name is Chou Niku, according to DigiFlonne.com. They have scans of it all too. (Well, not the D3 light novels.): http://www.boukenshin.net/disgaea/novel.php
Since I don't know how to make artist-color tags, I'd appreciate it if someone did it. Thanks! :)