When fighting Shichika in episode 7, Nanami mentioned her Clairvoyance, but she never said anything like that when fighting the Maniwani earlier (in episode 4, I think).
Was her Clairvoyance what allowed her to copy Maniwani's Kempo, and she just didn't name it in earlier episode? Or did she learned Clairvoyance somewhere else after she left the island, and as such she never had it when the Maniwani attacked her? And if it's the latter case, where did she learn it?
Wikipedia article:
Hidden technique: Migeika (見通し研修) - Nanami Yasuri was born with the eye of gods, with this ability, she is able to see through any technique, any movement, any weaknesses, thus mastering any ability with observation.
The clairvoyance Nanami is mentioning was Migeika, her special technique. Nanami is literally saying that she can "see everything."
Around 8:20 Nanami says, "I can see through any technique, any movement and any weakness." This is the closest in both fight scenes where she mentions any sort of clairvoyance implicitly. However, I didn't see her mention clairvoyance directly at all.
At 11:44 Nanami says, "And I've absorbed all of them. With these eyes." She doesn't say she has clairvoyance (which is a see all: "he supposed faculty of perceiving things or events in the future or beyond normal sensory contact." Google Definitions). Think of Migeika as more of an ability to take in every bit of visual information and process all of it and understand all of it as it is. In this sense, she can take in everything in battle, process that information and immediately understand and make use of it.
Through out the show it is explained though that Nanami has this technique, you simply missed it. It's especially mentioned in episode 4 where she fights the Insect Squad of the Maniwani.
