She is Sayu from Hige wo Soru.
She is rich succubus with assholes parents who had a close friend that was often bullied. This friend commited suicide and her fucked up parents trying to blame Sayu for some reason. She couldnt endure it so after his brother offered her some money she took it and ran away to stay away from his family.
But she commited the mistake to totally disconnect from them, even the brother, going to another far away city and throwing away her phone. Eventually, she had no more money to rent a room, go backm or buying food.
So she started sleeping with random men to get a place to stay and food. About seven guys later -accoding her at least- she ends up meeting the MC who is the first guy to offer her a place to stay without wanting to fuck her, and so the "romance" begins.
So yeah, wasnt exageratting. She is a literal slut -a prostitute-.