The publishers wish for these to be listed as separate series to represent each pack on its own, but it is my opinion that they should all be in the same series. The characters are very inter-woven to the point that one of the couples belongs to both packs. I have labeled them by the way the publisher intends them to be listed on their series pages but the reading order page are in the order in which they occur. I also combine them for the series breakdown pages. One would be robbing themselves of the full experience by not reading them all!