Seems like we're barreling towards an anime-original ending. Although if I were to make a bet, I'd bet that we don't get a "true" resolution to either the curse or the love triangle in the next episode. Although that image of a black fluffy haired in next episode's preview could be a harbinger for Junpei. AIC has balls if they decide to end the season on a cliffhanger like that. I'm not typically a fan of cliffhangers, but I'd totally dig that. But anyway, enough speculation about the finale, this is about the penultimate episode.
Nyan Koi, episode 12 – Right back to start (Season finale)
And so concludes the first season of Nyan Koi with the love triangle right back to where we started and Junpei having survived the harrowing trials of turning into a cat.