This essay explores the role of commentaries and translations in the interplay between classical Chinese and vernacular Japanese and between high (Heian period aristocratic) vernacular and demotic vernacular. Japan was largely a biliterate culture in the Heian period and earlier, with literary Chinese and kana-based vernacular existing side by side in the literary, religious, and political worlds. By the Edo period, however, high (Heian) vernacular Japanese had become almost as distant as classical Chinese for commoner readers. In this context, demotic vernacular translations of the Heian Japanese classics became a very important mediator between new readers and the Japanese classics. I argue that there were two fundamental kinds of translation, between literary Chinese and Japanese high vernacular and between Japanese high vernacular and demotic vernacular (what I call intervernacular translation). I focus on the important role of commentaries, which functioned not only as intermediaries between classical Chinese and vernacular Japanese but as a major force in the production of a wide range of genres, from poetry to warrior tales (gunki-mono).