the study of sentence styles, called stylistics 文体論という文体研究 - EDR日英対訳辞書
According to Masaru AOKI who studied under the supervision of Rohan, he taught literary theory and criticism, including studies on Japanese rhetoric (the history of Japanese stylistics), "Soga-monogatari" (The Tale of the Soga Brothers), "Wasan" (Buddhist hymns in vernacular Japanese) and Monzaemon CHIKAMATSU.
露伴の指導を仰いだ青木正児によると、日本文脈論(日本文体の発達史)・『曽我物語』と『和讃』についての文学論・近松門左衛門などの講義内容だった。 - Wikipedia日英京都関連文書対訳コーパス