Uuuuhh.... im conflicted, on one hand i rlly enjoy reading taboo, abnormal, forbidden, weird, etc romance stories. N i certainly do find the whole oppressor x victim romance to be an interesting trope but idk... this one just got a bit too real...? N i cant completely hate the kidnapper either since he himself was abused the same by his mother. Which im not sayin is a valid justification for his actions and all of the terrible things he's done towards the mc but tbf to him that's the only way he knows how to show his "love?" For her since that's the only love he's known/received. Again not a valid reason but understandable y.
Also even though this doesnt really fit into the category of josei it doesnt really fit into any others either. Maybe a seinen would be more fitting but definitely not shounen or shoujo. Although i would say i do understand that it was categorized as a josei tho, idk how to explain it but it has a bit of that joseiy feel to it.