slight spoiler:
i'm pretty sure the duke boy is gonna be ML. he's the only male character that she is self-conscious around. all the other guys are just family or children to her. though i suppose Harrison is 2nd ML as she does treat him as more of a peer rather than a child. also... (from here is kind of a spoiler, kind of my opinion):
I suspect duke boy also has memories from their past life... the way he treats her and the things he does for her imply some personal future knowledge about her.
No he definitely is from the past life, In one of the chapters he says that he didnt want to make calliope miserable in this life.
I am on chapter 27 and I’m just wondering what chapter my going to meet the male lead on