4 ideas
After finding a letter in her husband Kaneie's box addressed to another woman, the author had him followed and learned he was visiting a new lover on Machi-no-kōji. When he later knocked at her gate before dawn, she refused to open it and sent him a poem instead: 'Do you know how long a night can be, spent sighing alone until it breaks?' Her refusal gained her no leverage; soon his carriage was passing her house without stopping.
The diary opens by arguing that the popular tales of the day are fabrications that flatter their heroines. It proposes instead to record plainly what one woman of ordinary standing actually experienced, as a corrective answer to anyone who wonders what life with a high-ranking man is really like.
In Heian visiting marriage (kayoi-kon), the husband lived apart and came to the wife's house at night when he chose, often with several wives at once. Her emotional life became organized around reading signs such as carriages passing, delayed letters, and excuses. The structure turned waiting itself into the chronic condition that produced her jealousy.
Between the spouses, reproach, pleading, and reconciliation are conducted largely through exchanged waka rather than direct speech. The poetic form lets resentment be voiced with deniable wit, and a clever reply can defuse or deflect it. Reading the diary this way shows that the formal convention both enabled her to speak her anger and let him answer it with wordplay instead of change.