No, this isn't a doujin. This is one of the official light novels, Enterbrain's 9th volume, specifically. It follows the D1 continuum, but it's a cracktastic crossover for some...reason. Something about a picnic. It's really more a series of short stories than a novel. There aren't any translations (and I'm starting to think there won't EVER be /cry), but you can see the illustrations at DifiFlonne~ (http)://www.boukenshin.net/disgaea/novel.php