Yoshiro ishihara's detention in siberia written in “bokyo to umi” (FWMT)

In this article, we will consider the Siberian detention depicted in the essay “Bokyo to Umi” by Yoshiro Ishihara, who was known as a poet. Yoshiro Ishihara talked about his Siberian experience in poetry immediately after his return to Japan. Ishihara often stated that he did not write prose, but fifteen years after returning, he published several essays on his experience of detaining Siberia. Later, it will be published under the title of “Bokyo to Umi”. Why did he have to write his experience as an essay after fifteen years had passed? In “About“ Bokyo and the Sea”, there is the following description about it.