Plenty of harems have a girl who has a horrible backstory, a girl who lives a life buried in despair and desperation, whom the hero "saves", sometimes literally and sometimes just by somehow creating a way for the girl to find hope once more. I was wondering if there were any harems with several such girls.
Three great examples of this type of girl come to mind: Lily from Danmachi, Sinon from SAO and Raphtalia from The Rising of the Shield Hero (nicknamed Shieldbro).
Spoiler for Lily:
Lily had everything taken from her time and again by adventurers with enough strength to be full adventurers rather than "mere supporters"; when she ran and created a happy life for herself, they destroyed it and forced her to return to them. She's become incredibly jaded, quietly cheating as much as she could out of adventurers who had no problem taking everything she owned as if it was their right, trying to make enough money to buy her way out of her "familia" while knowing that a single moment of bad luck would have her punished for trying to "keep money from her betters" and stripped of all her possessions. Then Bell came along and was completely different. He always gave her an equal share of everything they gained as if it was obvious, trusted her as a dear friend, and fought to come to her rescue even after she tried to kill him and stole his most treasured possession. When she saw him come back and save her despite everything she'd done, and continue to accept her even after she spilled all the ways she'd cheated and stolen from him to that point, she broke down completely. For the first time, she found someone who actually cared for her, who valued her and treated her as a friend, and who viewed her as his equal deserving of true respect.
Spoiler for Raphtalia:
Raphtalia was a demi-human, a beast human with tanuki ears and tail. She'd lived a happy life for the first ten years or so, growing up in a village that protected beast-people from the prejudices of the humans of the kingdom. Then a wave of monsters overran her village and killed many people, including her parents, as she watched. She tried to give people hope and convince them they could rebuild, but almost everyone was captured by soldiers who sold them into slavery. She witnessed her best friend die at the hands of a man who literally sought to bring as much fear and pain and sadness to her as possible. When she finally wound up being bought by the hero Naofumi, she was sick, broken, and full of terror. But Naofumi gave her whatever she wanted without her ever asking. He supported her, held her when she slept to help suppress the panic attacks she had at night. The only thing he ever forced her to do was fight. Bit by bit she came out of her shell, regained confidence and security and came to feel a bit of hope once more.
I love these sorts of characters. It's not that I like harem members who feel some sort of dependence or gratitude or anything. Rather, it's just that I love the brightness you see in them. Light seems so much brighter when you see it after escaping a dark tunnel, and for this sort of character the world truly comes alive for the first time in a long time, bringing about some incredibly touching scenes and a bright personality that I just love. It's for this reason that I'd like to see if there were a harem series with more than just one or two girls who'd been thus pulled from the abyss, so to speak.