The story is pretty average for an incest anime, one sibling loves the other and decides to act on it. In this case, it's the brother who decides his sister needs some lovin'. I'm terribly sorry for that phrasing, but whatever. It's how I think in my head. The only thing that steps the story up is the fact that the sister is going to move away soon, so the whole thing has a kinda sad tone to it because they won't get to see each other afterwards.
The art is pretty awesome. I love the character designs because they are original and both of the characters are attractive and cute. It's a shame that the animation is a bit of a let down because the sister looks gorgeous and some of her facial expressions were amazing. For example, after they had sex one time, she had her face covered because she was embarrassed. She then lifted her hands from her face, she had tears in her eyes and she just said "baka..." quietly. It was so cute!
"Was there a soundtrack in that hentai? I couldn't tell because of the moaning". That's true of all hentai, with the exception of Bible Black with the main theme, just called "Bible Black" from the original game. It's awesome, check the music out if you haven't already. Anywho, back to Ane Koi. The voice acting. In Japanese voice acting, there seems to be tow types of guy. The burly voiced guy who sounds like he smokes like a chimney, and the young guy who sounds like he barely hit puberty. Here, we have a young guy. I love the brother's voice so much. He does an awesome job of sounding sweet when he has to, but assertive during the sex scenes, since he's always in charge. The sister's sex noises were outstanding to me at some points, and have really stuck in my head. She keeps the cute tsundere aura about her at all times, and is super cute. She's actually a likeable character.
I enjoyed this immensely. I was rewinding scenes, and they were all very good to the point where I can't have a favourite part of the show. The flashbacks in the second episode were a bit like, "Yeah, I watched that 2 minutes ago", but that's my problem I suppose, for being a hentai-marathoning perv. I like hentai like this where there is no weird shit in it, just lovey dovey sex scenes. Oh, an incest. This is the price I pay for watching so much hentai, I guess. I will be a female pervert forever. I regret nothing. Except for that pee-drinking bit, that was kinda gross.
