This research explores the phenomenon of Dreaming Girls (mengnü), a subculture of young women in contemporary China who form romantic attachments to virtual characters—primarily drawn from anime, manga, games, and other digital media. Far from being a marginal or socially isolated group, Dreaming Girls include students, professionals, and creatives who actively craft fantasy relationships through digital practices such as diary-writing, fan fiction, cosplay, and the commissioning of personalized illustrations. These women also create "virtual selves," often embodying male personas, to construct emotionally resonant narratives with their chosen virtual partners. This study interrogates how Dreaming Girls negotiate intimacy, gender, and identity in a sociocultural context marked by heteronormative expectations, patriarchal values, and declining marriage and fertility rates. Drawing on long-term participant observation and interviews with Dreaming Girls on Chinese platforms like Weibo and Rednote, the research examines how these practices blur the line between fantasy and reality, challenge traditional gender binaries, and transform the emotional landscape of love in the age of AI-mediated interaction. The study also considers how virtual romantic engagements are shaped by platform economies, fan hierarchies, and broader structures of power. Ultimately, this work argues that Dreaming Girls reconfigure what it means to love, desire, and be gendered in a digitized, posthuman China.