The little stream of the Minano-gawa river coming from Tsukuba falls into another stream, and gradually enters oblivion; when I think of someone I love, my feeling is same as the Minano-gawa River; it seems to get deeper and deeper' (in "A Hundred Poems" it is given as 'en to nari nuru' (instead of nari keru).
「つくばねの峰よりおつるみなの川恋ぞつもりて淵となりける」　（百人一首では「淵となりぬる」）