Fujiwara no Korefusa 藤原伊房 (1030–96) was the third head of the Sesonji 世尊寺 family, a famous family of calligraphers. Previous scholars have made numerous attempts to gain a grasp of the actualities of Korefusa's calligraphy, but their investigations have been inadequate, and to the best of my knowledge none have touched on the formation of his calligraphic style. In this article, I accordingly examine the origins of his style, exploring the works that he may have seen and utilized when developing his own calligraphic style.
  The paper used in the Jūgoban uta-awase-gire 十五番歌合切, attributed to Korefusa, is currently thought to be Chinese paper produced during the Northern Song. The fact that paper entered Japan from China suggests the possibility that Korefusa may have seen writing from China too. When one examines records dealing with Japanese monks who went to Song China and merchants ships that came to Japan from the Song, there emerges the possibility that even in the current of Japanization that resulted from the abolition of Japanese embassies to the Tang cultural exchange may have occurred between Japan and Song China. It is also conceivable that Korefusa may have had the opportunity to see Chinese goods that entered Japan via Khitan, which was engaged in smuggling. When one then examines Korefusa's calligraphic style, it is possible to detect in it signs of his acceptance of the calligraphic techniques of Yan Zhenqing 顔眞卿 and the Song.
  In addition, correspondences with the gourd-shaped patterns in a sheet of the Sunshō'an shikishi 寸松庵色紙 held by Gotoh Museum and in the Songfengge shijuan 松風閣詩卷 by Huang Tingjian 黄庭堅 and a statement in the Gekanshū 下官集 that Korefusa based himself on Song methods of writing all merit attention as evidence of the influx of things Chinese. It is to be surmised that Korefusa developed his strong masculine style of calligraphy by incorporating Chinese calligraphic techniques even as he was learning the calligraphic style of the Sesonji family.