In the novel it didn't feel forced at all, I feel like they forgot a bunch of panels

Umm where did you read the novel? And from which chapters is Ein and Karina's love story starts in the epilogue?

I read the novel in Spanish and if I remember correctly I think it was the side stories (chapter 200 or something). I read the novel about 4 years ago so my memory is a bit foggy. I can't seem to find the link. Sorry