Kuroko is a member from the legendary middle school basketball team known as "The Generation of Miracles", and while nobody seems to know about him, the main five players of the team all admit that he is the strongest member, the phantom sixth player. When he joins the high-school basketball team, everyone is surprised to find out that he is small, weak, and easy to miss. 
What is the secret that makes him so strong, and how will he help his high-school team?