Nah. There's no novel. It's just from what we've read so far I think we only have two arcs left for the main leads... We saw them confess to each other and had Kyoko deal with her past so now it's Ren's or more like Kuon's turn to deal with his past... Also Kyoko finding out about Kuon (but I'm not too confident on both being solved at the same time since we might still have to deal with Sho at least once more).
The awaited arc has always been Ren's past because it has always been hinted at but never fully divulged.
The reason why I think we're finally getting the whole story and not just getting baited again is because they are in Kuon's home, he has the stone back and because Kyoko (who can now help him by openly expressing her love) is there through the means of a very convoluted excuse of being a P.A.
It's starting because Kuon went to Rick's gravesite
The awaited arc is finally here ヾ(☆▽☆)