This sort of question frustrates me. You have made half of a decision -- to do some sort of thesis on Japanese TV -- but you can't think of how to pinpoint the actual premise. Why would you ask us? It's your major. Are you studying communications? Culture? Language? Advertising? Drama? Without any of that knowledge, how can we even begin to do your thinking for you?
Tell us that much, at least.
Also, tell us why you even imagined Japanese TV (such a broad topic in just 2 words) came to your mind in the first place.
I hope you don't ask us to write parts of it for you, too.