If I attempt to translate more literally I get…
Watashi ni wa sonnani omoshirosou ni wa miemasen.
It does not look very fun to me.
What purpose does the second “ni wa” serve? There wasn’t anything about it in the audio lesson other than a note that it’s repeated, and Module 4.7 doesn't clarify.
Watashi ni wa … sonnani omoshirosou … ni wa … miemasen.
To me … looks very fun/interesting … [ni wa] … doesn’t seem.
It doesn’t seem [ni wa] look(s) very fun/interesting to me.
Following some research, the only thing I’ve come up with—and may be completely wrong about--is that “ni” can literally be translated as “to,” and “wa” is used a second time not as a topic marker but as a means of either Kenny emphasizing how manga looks to him or to denote contrast (i.e.: versus Sayaka saying manga IS interesting).
If I’m correct with “ni” translating to “to,” I don’t understand how or why other than that "ni" is often a destination particle ("ni" often = "to") and the sentence makes more sense (from an English grammar perspective) with the word “to” in there.
As for “wa,” my guesses of emphasis or contrast are just guesses, no more. If I’m wrong, I don’t understand why; if I'm right, I don't know which.
As for “ni wa” as a whole, then, I suppose I get the gist of the combined usage of particles if my guesses are accurate, but if my guesses are incorrect, well, then I’m pretty clueless.
What’s going on here?
Thank you for the help!