Board Thread:Episode Discussions/@comment-32617252-20180429034507/@comment-33372361-20180502203652

At this point, KK being either a bastard child (since Jiraiya was fooling out a lot), or one of Minato's teammates are actually the thoeries that make more sense. Remember that the one who invented Rasengan was created by Minato first, which he based on the Tailed Beast Ball. Since it also took him three years to complete it, it would make sense if he was 'helped' or watched by one of his teammates in the process which would explain how KK knows Rasengan.