There are two opinions about this Sumori Monogatari: one is that it was complementally written by posterity based on Uji Jujo (The Ten Quires of Uji), and the other is that Sumori Monogatari including 'Chapter of Sumori' was once written by the same author who made the original story as a tale which took place after the death of Hikaru Genji, but for some reasons, it was thrown away, and later the present Uji Jujo which focuses on Ukifune was rewritten.
この巣守物語については、宇治十帖を踏まえた後人の補作であるという説と、本編と同じ作者により光源氏死後の物語として「すもりの巻」を含む巣守物語が一度書かれたが、何らかの理由で破棄され、その後改めて浮舟を中心とした現在の宇治十帖が書かれたのではないかとする説が存在する。