Hard manga....Because of the topic. Execution was weak and stupid. I've known cases similar to that in real life but............there are many but's in that. The girl's depiction was more or less real as for the guy(s) it wasn't. It felt more like author knew the girl but got fragmented knowledge about the guy. Maybe i skipped though some dialogue and didn't understand due to poor translation in some moments.
The girls depiction is real for multiple reasons, she was forced to grow fast. Tragedy after tragedy kept happening to her and then a scumbag came. To us he is a scumbag to her though? He was the knight or a prince that she was waiting, her love for him is explainable. He gave her security in the most troubled time, he gave her new experiences that she didn't have, he gave her warmth that she didn't have.
As for the Mr.Scumbag.....I don't know, hate for his brother? Doesn't seem correct, this child is a trophy of his brother being cucked. Plain and simple pedo? Yes and somehow no, since we have seen him return to her when she was already grown up, while she was sweeping the street......Opportunity? That's sick.
I've even decided to quickly check Usagi Drop due to first commentator and well these mangas don't even come close together. In Usagi Drop, guy needed a lot of time to transition from feelings from father to partner and he was hesitant(plus he waited until she turned 18, just to accept the possibility). He was left with no choice, his step daughter basically was ready to become old maiden just to care for him.
As for this shitstorm? Too predatory and transactional, i expect this sort of relationship in a war torn state where humanity and decency is killed by the bullets....
P.S. While writing this comment decreased the rating in my library for this. Writing helps sometimes to take a deeper dive in what you have just read. And I understood that while girls depiction was ok, everything else crumbles as a story.