The political intrigue is the reason I fell in love with Saiunkoku Monogatari, a series made up of two 39-episode anime, which are an adaptation of part of a soon-to-finish light novel series. The first seven episodes are typical light-shojo with a dusting of politics, but it eventually develops into a show that has one plot-arc driven by the economic and political consequences of contaminated salt. I love this story.

It won't count as rare if the fandom-specific challenge running for more than two years rule makes it to the final cut, but it fits the other rules, so I thought I'd throw it out.