Anna M. Shields has written a marvelous book on friendship, literature, and history in medieval China. One Who Knows Me: Friendship and Literary Culture in Mid-Tang China(Harvard University Press, 2015) is the first book-length study of friendship in the Chinese tradition. Focusing on the period from the 790s through the 820s, it asks how writing on friendship both reflected & shaped broader transformations in mid-Tang literary culture, and it weaves together historical and literary analyses in offering its answers. Shields begins by laying a foundation for understanding how the changing social & political conditions of the late eighth & early ninth centuries encouraged friendship practices among elite men and the representations of those practices in texts. The chapters that follow are roughly organized according to the life-course of Tang literati, from early writing for patrons and exams to funerary writing that marked the death of friends. It's an exceptionally accomplished study that weaves together compelling argumentation and moving translations from primary source material, and it deserves a wide readership.
For more of Anna's work, check out her academia.edu site: http://princeton.academia.edu/AnnaShields