It is a clone of Slamdunk with worse characters, poorer graphics, and a more depressing storyline. If you like to watch excellent teams and better players beat up an already disadvantaged team with only seven player only three or four of which can play decently, no proper coach, no proper adviser, non existent training, a dissolved club, this is the show for you.
I have watched so far 24 episodes and I can tell you that it is really great! I can say the mix of haikyuu because the protagonist is short but its not logic because Ahiru no Sora manga release in 2004 while Haikyuu is 2012.
First of all, it takes 15 episodes to finish a match... Same thing , repeating & repeating.
Excellent anime for basketball lovers, very entertaining and fun with good explanations of plays and good stories in the characters.
All I got to say is that if you are looking for a different basketball/sports anime then you should really watch it. All the characters get their shine and you get to see some close-to-realistic basketball play.