Story wise, plot is the same with the anime skipping some parts here and there. But the anime gives the impression that the director read the manga and went,"Screw this. Let's just wing it, have fun and go full camp with this."
It's overall more mindless fun, more edgy-ness, more glorious sunlight, more random Rin death scenes, more heartwarming, more outright incest, more campy saxy (Yes, it's so sexy it becomes saxy) jazzy soundtracks, more Eiji x Rin, more defiance of basic laws of physics, more innuendo, more smile inducing and more jaw dropping (Edgy-sama. I'm pregnant). And they take the time to draw food- lots of food. Considering the source material, it's B-movie anime gold in its finest form, on par with the works by veteran studios such as Ghibli, feel, White Fox, Madhouse and ufotable.
The anime is not a mere adaptation of a manga about Edgy-sama trying to save his beloved non-blood related imouto. It's a Gilgamesh and Homer level epic about a small studio's rebellious warcry against the gods who sneer and mock at them while tossing their endless divine arsenal of bad source material, flat characters, deus ex machinas and illogical plot twists upon humanity, just as Zeus chucks lightning bolts against any mere mortal who dares to defy him and scale Mount Olympus.
On a serious note, it's not "Anime of the year" material, but it's a strong contender for the "Considering the budget and source material, you gave it your best" category if it exists. It's so bad it goes full circle to awesome. It makes you want a season 2 just to see how the studio is going to save the final post-chapter 32-33 arc.
