SPOILER ALERT :: Read at your own risk
Yeah, seriously, I get why there's so much negative reviews, I admit there's a lot this manga needs to really work on. But it's good points are...well...GOOD.
There definitely are incest themes here, or just too much sibling love to the point of creepiness, but it's that love that the entire story revolved around on. What a brother can do just for his sister, and vice versa. It's amazing, to think that their ways of thinking are actually messed up by our standards, but those decisions can still tug a heart string.
The gore, I eventually got used to, 'cause for me, it serves as an intensifier of the experience. Although sometimes, it can distract me to the point of not even giving a shit about what's going on since it takes all my willpower to keep from barfing all over the place. Yep, the author needs to work on that, I guess. Gore is awesome...in the perfect amounts and in perfect circumstances only.
Lastly, the art. Yeah, it's pretty generic shoujo style, but I adore how it looks sketchy and rough. It's probably only me, but I love it when the art style helps set the mood of the entire premise. Also, how it contrasts the nature of the plot - so much gore subjected to cutesy characters.
Now that I got that covered, I'll discuss some things that I didn't like:
The Plot :: I don't hate, no. It's just that it almost felt random. Like some bored god just thought of something fun to do, and what better things to cure his holy boredom than put a pair of abused siblings in the sorriest chain of events. So far, there wasn't much development on the virus that destroyed both their lives, and I really got pissed off by that.
Lack of development for potentially-important Sub-Characters :: The siblings were very well-developed, but the side-characters aren't. I know it isn't a necessity to do so, but in the manga, I think it is. This mysterious big-boobed chick from this research organization, the father (who, for some reason, really seems important) or the organization itself. In my opinion, there's too much focus on the main characters, and too little on the ones who actually are the cause of all this shit going on.
Yep, Pupa is a potentially good manga, but I've read about 10 chapters so far so I will be updating this review once it's completed.