While I Was Young, My Yandere Sister Tried to Hide Her Beauty in the Golden House

The young male protagonist Lin Xuan is fostered in the shared apartment of his 19-year-old stepsister Roy because his parents have reorganized their family. On the surface, he has a venomous tongue and a cold tongue, but his two roommates who live in a shared school building also treat him as a soft persimmon. However, this is a world where everyone is yandere. Roy's venomous tongue and disgust are just to cover up her pathological desire to control this beautiful "little troll" as her own and cut him off from all contact with the outside world. The other two heroines also have their own plans for the yandere's imprisonment (secret room creation, location tracking, exclusive imprinting). The male protagonist seems to be a lamb waiting to be slaughtered, but in fact he is a sober hunter. He uses his appearance, age advantage and system to pull to the extreme, turning these high-ranking school beauties step by step into reverse PUA, and finally changes from "caged birds" to "rope holders".