@Khirud It's working in fiction. In this story you could see that she is really changed.
But in reality 99.9 modern girls with such experience and behaviour would be huge red flag and this kind of relationship would drive almost everyone mad, because you just cant trust her and her history.
But again, in this manga you really see a transformation and a new start with remorse.
@Nba RussianFan yeah I got what you are saying I don't mind a girl being a virgin or not or having few ex but still the thought of her being used by so many people