Which arc are you going to react to next? If you follow along โMonogatari 2nd season TV animation seriesโ it would be Otorimonogatari(Nadeko Medusa), if you strictly follow the order of book release, it would be Hanamonogatari(Suruga Devil). I personally think itโs better to react to Hanamonogatari first, since it is written before the later arcs of 2nd season, and Nisioisin did sprinkle some small lines that reference to Hanamono here and there in the later arcs. But itโs okay either way, since Hanamono is a very separate story from the other arcs of 2nd season.