Board Thread:Theories and Speculation/@comment-24824859-20150212011837/@comment-1512913-20150214130251

Naruto and Minato are the only 2 known people who can convert/adapt chakra like that and "coincidentally" both can use chakra modes. Not to mention Kurama's chakra turns yellow in chakra mode (color of Naruto's) and gains a signature much more similar to his, such that sensors sense Kurama's chakra in chakra mode as Naruto's, not sure how much evidence is there needed.