This paper concerns the meaning of a puzzling main category name used in the extant oldest anthology Man’yōshū in Japan. The term “sōmon (相聞)” was originally from ancient Chinese without question. However, scholars are confused with its usage as a category name for it never seems to be used in this way in any extant ancient Chinese anthologies or literary collections before Man’yōshū, which was compiled in the 7^th - 8^th century. Since many waka (Japanese poems) collected in this category contain love/romantic expressions, “sōmon” has been considered a synonym of the term “renka (恋歌love song)” by later generations of Japanese scholars.

     In the paper, I discussed how the term “sōmon (相聞)” has been misinterpreted as meaning “love song” due to an incomplete understanding of the function word “xiang (相sō in Japanese)” that precedes a verb in Chinese. The character “xiang (相)” is commonly defined as “mutual” in both Chinese and Japanese sources, leading to the assumption that “sōmon (相聞)” means “to greet each other” or something similar in the context of romantic relationships. Based on several authoritative dictionaries of Chinese function words, this paper examines the usage and meaning of the two characters “sōmon (相聞)” in the context of ancient Chinese.

     This study revealed the long-neglected meaning of the function word “xiang (相or sō).” In addition to the meaning of “mutual” mentioned above, the character also acts as a pronoun that refers to the opposite party of the action indicated by the verb that follows it. Namely, “sō+mon (相+聞)” can also mean “to pass a message to someone” in ancient Chinese, and the recipient can be anyone, not limited to those in an intimate relationship. This meaning was also in use in ancient Japan during the Nara period (7^th-8^th century) at the latest. The study explains why some wakas that do not express “love,” and those that do not have reciprocal chanting, have also been classified as “sōmon (相聞)” in Man’yōshū.