My Beloved Little Sister Was played To Marry A Middle-Aged Man. Eimi Fukada

The story revolves around a dystopian society where a reproductive promotion law enforces marriages between young women and older men to promote fertility. The plot explores the complex and disturbing relationship between Yongmei, who is forced into marriage, and her elder brother, highlighting themes of coercion, power dynamics, and the blurring of familial boundaries.