楊逵（本名楊貴，1905-1985）是日治時期臺灣重要日語作家之一，一九三四年，他的日文小說〈新聞配達夫〉獲得東京左翼文藝雜誌《文學評論》創作獎第二名（第一名缺），成為第一位受日本文壇肯定的臺灣人日語作家。一九三六年，胡風(1904-1985)將這篇小說翻譯成中文〈送報伕〉，刊載於上海出版的雜誌《世界知識》，後又收入《山靈－朝鮮臺灣小說集》、《弱小民族小說選》。楊逵八十年的生涯可以說和臺灣近代文學發展密不可分，特別是一九三五年創辦《臺灣新文學》雜誌，在臺灣文學發展史上發揮過核心作用。楊逵生長在殖民地時期的臺灣，自幼接受日語的初中等教育，他的文學啟蒙主要是透過日語而知曉世界文學，而讓年少的楊逵立志於文學的關鍵人物，就是公學校（日治時期臺灣總督府的歧視教育政策下，臺灣兒童所就讀的學校）日本人教師沼川定雄(1898-1994)。根據楊逵的回憶和訪談記錄，他就讀公學校時期，經常住宿沼川定雄的家，接受其懇切的課業指導並閱覽其藏書。對楊逵而言，與沼川老師的相遇大幅度的改變他對日本人的觀點，同時也為楊逵的學問奠定基礎。本文根據調查資料，概觀沼川定雄的生平，並嘗試考察他與臺灣以及他與楊逵的關係。

An important figure in the literary movement of modern Taiwan, Yang Kui (1905-85) also produced several novels in Japanese during the colonial period. In 1934, "A Newsboy," one of his most noted short stories, earned him a literary prize from an important Japanese journal. This piece was later translated in to Chinese by Hu Feng (1904-85) and was included both in Mountain Spirit: Short Stories from Korea and Taiwan and Anthology of Stories from Weak and Small Nations in the World. Yang Kui played an important role in the development of Taiwanese literature; one of his contributions was the founding of the literary journal Taiwan New Literature in 1935. Yang was born and educated in the Japanese colonial period, and his early exposure to world literature was through Japanese translations. In a talk late in his life he mentioned Numakawa Sadao (1898-1994) as one of his teachers from Japan who had a formative influence on him. Numakawa was a young teacher in a gong xuexiao, an elementary school for Taiwanese children during the Japanese colonial period. He was kind to Yang, taught him many subjects free of charge, and granted Yang access to his book collection. Numakawa was a literary person himself and published some works in Japanese newspapers based in Taiwan. This intriguing friendship between an anticolonialist Taiwanese novelist and a Japanese school teacher, who was in a certain sense a symbol of Japanese colonialism, deserves critical attention. This article investigates the life of Numakawa in order to understand the significance of this friendship in the development of Yang's literary career.