Sookja Cho's Transforming Gender and Emotion: The Butterfly Lovers Story in China and Korea is an invaluable work that enriches the field of comparative studies in the East Asian literary tradition. The book explores how the Butterfly Lovers story emerged and traveled to different regions of China and Korea, and how its themes and narrative structure have changed in different historical times. China, Japan, and Korea share a premodern literary tradition centered on Chinese writings as the political and cultural lingua franca and the barometer of civilization. However, English-language scholarship has paid little attention to the transmission, adaptation, and transformation of literature among these three countries during premodern times.

The Butterfly Lovers is a love story about Liang Shanbo and Zhu Yingtai, who meet on their way to the Confucian Academy and fall in love while studying together. Ultimately, this leads to their deaths after Zhu's family arranges her marriage to another man. As Cho discusses in chapter 1, the story originated in Ningbo, Zhejiang Province, China during the Eastern Jin dynasty (317–420) and circulated widely during the Song dynasty (960–1279), traveled to Korea around the Tang period (618–907), culminated during the Ming and Qing period (1368–1911), and survived to the present day. This book focuses mainly on examining Chinese texts from the Ming and Qing period in comparison with earlier and more modern texts, as well as Korean texts from the Koryŏ period (918–1392).

The earliest written versions of the story, produced during the Song dynasty, were probably influenced by the rigorous social norms and Confucian values of the day. Therefore, more emphasis is given to the inner qualities and personality of the male hero, Liang, while the role of the female heroine, Zhu, is minimized as a Confucian characterization of a virtuous woman. More detailed elaborations on their love, tragic deaths, and happy ending in the afterlife, involving their transformation into butterflies and resurrection, were not added until the Ming and Qing period. It is also worth noting that the earliest text containing the expanded narrative of love and the butterfly transformation is the Korean Sipch'osi version, which was compiled around 1300, during the Koryŏ period.

This book examines the various motifs of the Butterfly Lovers’ narrative, integrated into various genres in different times and places, which challenge, negotiate, and compromise with the patriarchal gender ideology prevalent in premodern East Asia. Cho explores the cross-dressing and gender performance that Zhu undertakes to fulfill her desire for Confucian education, traditionally the domain of men, in chapter 2; the development of their relationship and juggling of friendship and heterosexual love in chapter 3; Liang's accompaniment of Zhu on her trip home, serving as momentum for the transition of their relationship from friendship to heterosexual love in chapter 4; and the religious elevation of Liang and Zhu to the status of deities through transformation into butterflies, signifying the reuniting of souls in love in chapter 5.

What makes Zhu's Confucian education possible is not only her willful attempt to cross the gender boundary, which challenges and disturbs the gender ideology, but also her negotiation and compromise with it. The conflict between the friendship pledged between Zhu and Liang as a man and the heterosexual love of Zhu's romantic desire persists until Liang visits her hometown for a reunion. However, despite delaying the fulfillment of Zhu's love toward Liang, this conflict allows them to establish a closer and deeper relationship during the time they spend together as friends. Liang and Zhu also show their attachment to traditional values and beliefs by realizing the Confucian ideals of a man and woman associated with junzi and shunu in Zhu's virginity oath and obedience to her family's arrangement of marriage, and in Liang's faithfulness to his studies and lack of discernment regarding Zhu's true sex. However, caizi-jaren characters enacting the tragic love of emotional and passionate young lovers with the gift of literary talent and beauty give more autonomy and agency to Zhu than shunu with the Confucian sense of virtue and discernment.

Zhu, against gender norms, plays a leading role in their relationship since Liang does not initially know Zhu's actual sex, but Liang is faithful to their friendship by offering his unquestioning trust and support for Zhu. The gender roles are reversed when Zhu transitions their relationship from friendship to heterosexual love during their parting journey. Zhu shows her desire to be recognized by Liang as a woman, hinting at her true gender identity, and takes on the role of leaving Liang behind, which is the male lover's role in traditional Chinese literature. Chach’ŏngbi in the Korean shamanistic text “Segyŏng pon p'uri” (Unraveling the myth of the agricultural goddess), which incorporates elements of Liang and Zhu's story, also highlights woman's self-autonomy in Cheju Island. Chach’ŏngbi is a daughter of a commoner but pursues her love for Mun Toryŏng (a son of the Northern Dipper god) by going through hardship and adversity to reunite with and marry him, eventually being elevated to the position of an agricultural goddess.

One of the merits of this book is its focus on analyzing narrative motifs and themes with the historical background of different times and spaces. However, it does not locate the various Chinese and Korean texts within the broader context of comparative literary history by exploring how the transnational literary exchanges through the story of Liang and Zhu illuminate the distinct features of the two literary traditions and their relationships with East Asian literary tradition. It appears as if the Korean texts are arranged based on their shared themes, rather than given independent attention in relation to the Chinese literary tradition. Although the book draws on a variety of texts from different genres distinct from the Western literary tradition, it does not sufficiently elaborate on these genres. Thus, it raises the question of how different genres emerging in other times and places might affect the way the Butterfly Lovers’ tale is integrated and transformed.