Kokugaku was an academic movement, a school of Japanese philology and philosophy originating during the Tokugawa period. Kokugaku scholars worked to refocus Japanese scholarship away from the then-dominant study of Chinese, Confucian, and Buddhist texts in favor of research into the early Japanese classics.

Philology is the study of language in oral and written historical sources. It is the intersection of textual criticism, literary criticism, history, and linguistics with strong ties to etymology. Philology is also defined as the study of literary texts and oral and written records, the establishment of their authenticity and their original form, and the determination of their meaning. A person who pursues this kind of study is known as a philologist. In older usage, especially British, philology is more general, covering comparative and historical linguistics.