Responses
In actuality, there's nothing really 'end' on the main couples' scene. But, the most where they were focused was only on vol. 1 and the rest of the volumes are kind of a side couples and other characters stories but still showing briefly the main characters (but in a form where they almost like a supporting character for the focused character ones). So, i can only say it is a bit random.
I can see why i actually forgotten about this for years now...
I still don't think it is worth reading until the very end (personal opinion). The author got too carried away by side characters and completely forgot the main couple. Also, some backstories are completely unnecessary, of they want to introduce new couples mught as well show them briefly and create new manga or story for them.