Narushima Ryūhoku (成島柳北) was a Japanese author and scholar who lived from 1837-1884. He was born in Asakusa, and his given name was Korehiro (惟弘). The Narushima family were okujusha (奥儒者), or Confucian tutors to the Tokugawa shoguns, who were also involved the editing of Tokugawa jikki (德川實紀）and other historical annals, including the (後鑑 Nochikagami）. Ryuhoku participated in these editing projects as a young man.
He served as tutor to the shoguns Iesada and Iemochi but was, according to some theories, dismissed because he wrote a poem critical of the fact that his recommendations had not been adopted. At that time he took up Western studies. During the Keiō period (1866-68) he served in the shogun's cavalry and also briefly as Minister of Foreign Affairs. After the Meiji Restoration, he took up a position with the Higashi Honganji Temple, which sponsored a tour for him and four other men to Europe and the United States from 1872-73. Soon after his return to Japan, Ryuhoku became the editor of the Chōya Shinbun (朝野新聞), and also founded the literary journal Kagetsu shinshi (花月新誌). He had a very critical attitude towards the great functionaries of Satsuma and Chōshū, who although vassals of the former shogunate, were now swaggering around in their new roles as leaders of the Meiji government. In protest, he declared that "I will become a useless person between nature", and started to write satire.
Ryuhoku's most famous work is "Ryūkyō Shinshi" (柳橋新誌), or "New Chronicles of Yanagibashi", the first volume of which he began writing in 1859, and the second volume of which he began writing in 1871. The work concerns the world of the pleasure quarters of Yanagibashi, humorously depicting cultural shifts from Edo to Meiji. "Kōsei Nichijō" (航西日乗), or "Diary of a Journey to the West", is the travelogue he wrote during his journey to Europe and the United States in 1872-73.