The commentary continues that while she was watching the moon reflected on the surface of the lake on the night of August 15, the concept for the Tale of Genji occurred to her and she began with the sentence from the chapter Suma, 'Thinking it is the harvest moon...'
そうしたところ、8月15日夜湖面に映った月を見て源氏物語の構想を思いついて須磨の巻の「こよいは十五夜なりと思し出でて」と書き始めたとしている。