Board Thread:Theories and Speculation/@comment-27082825-20150116155842/@comment-3279282-20150121004213

In chapter 315, it's called 得意なタイプ tokuina taipu, which means special type.

得意 can mean "one's strong point" or "one's speciality". And if every nature that you have is your speciality, none is. So yeah, while "affinity" wasn't used, it was said that one has a "special" nature, which is shown in the chakra paper.