otorimonogatari
Otorimonogatari ((囮物語, or "Decoy Story") is the tenth book in the Monogatari series of light novels. It was animated as part of the anime "Monogatari Series: Second Season", which aired in 2013. It contains the story Nadeko Medusa, protagonized by Sengoku Nadeko.
This tag implicates monogatari_(series) (learn more).