How do prose and poetry interact in Tales of Ise?

Ariwara no Narihira's Tales of Ise is a type of Japanese literature called uta monogatari, a sub-genre of monogatari (an epic narrative using extended prose) that combines waka poetry and sections of prose. In this particular case, the poems make up the bulk of the "narrative," with the prose occurring very briefly, usually only to establish the scene, introduce the next poem, or comment on a poem's composition. In many instances, these narratives start with the same beginning: "Long ago, there was a man" (or, "Mukashi otoko arikeri"). Because of the way that it is arranged, the book lacks a traditional plot, and the sections are best connected through the presence of a narrator. The book consists of 125 sections with a total of 209 poems.