Kuroko is secretly a Ninja.He can turn invisible to throw off opponents and allies. And you thought Ninjutsu (no, not that one) is useless in basketball...
Kuroko dyes his hair.When he was young he started dying his hair blue in order to be more noticable and it actually did help. For an appropriately important game he'll eventually go back to his natural black and be even more invisible than before. (And by extension, he wears light blue contact lenses to match his hair as well.)
Akashi and Kuroko are related.Pops up a lot in fanfiction for some reason, and they do look pretty similar.
Kuroko will go into the Zone against Rakuzan, and use Akashi's skill against him.Akashi's skills would suit a Weak, but Skilled character like him.
The truth about Kuroko backstory that he is going to reveal in Chapter 204 will has something to do with Akashi.
The reason behind Haizaki's treatment of Kise is because he doesn't want Kise to call him Haizakicchi.Considering that a bunch of other characters also don't like the nicknames he gives them...