Series: A princess which is? (yuppiyupitaro)

http://www.pixiv.net/member_illust.php?mode=medium&illust_id=61165394

Story involving bullying pet yukkuri before eventually killing them. First half involves a nicehead komaricha while the second half involved a koreimu that's less niceheaded (but not exactly a shithead).

In the final page it's revealed that 2 anons are playing tic-tac-toe, using koyukkuris they've raised as pets to draw the X and O