This article focuses on the literary criticism of the Edo-period scholar, Seita Tansō (1719–1785). Although a historian by vocation, Tansō additionally lectured extensively on the Chinese vernacular novel, Shuihu zhuan (Jp. Suikoden, En. The Water Margin). While earlier generations of Chinese fiction aficionados in Japan had also discussed Shuihu zhuan, early eighteenth-century analysis was primarily limited to philological explication—a task necessitated by the extensive use of colloquial language in the novel. In contrast to this tradition of philological exegesis, Tansō turned his attention to the ethical content and literary structure of Shuihu zhuan. Tansō was heavily influenced by the writing of the Chinese fiction commentator Jin Shengtan (1608–1661), and in this article, I discuss Tansō's use of Jin's fiction criticism in the construction of his own interpretation of the novel. I argue that the dissemination of Chinese novels in Edo-period Japan cannot be discussed without an understanding of Japanese engagement with Chinese narrative theory, and I identify Seita Tansō as an important figure in a transition from philological to more purely narratological analysis of Chinese vernacular fiction.