This isn't even my... third time seeing a sequel in this situation where it takes place between two parts of the final chapter of the previous series? It might be the fourth or the fifth. Not sure without putting too much effort into thinking about it. Nana to Kaoru, for instance, just had a sequel start up some time back but this is actually the second one of those and it takes place before the first sequel did, so by release dates is really wonky over there even though the chronology is gonna be pretty straight forward eventually when the current run is done (hopefully, I guess they could make it even messier too). Shit happens when you're not necessarily sure you'll be allowed to continue a story, or even want to do so, I guess.