The narrator adopts the stance of a woman keeping a diary, a device that lets the author write intimate vernacular prose in a native script rather than the formal Chinese reserved for men's official records. The borrowed persona licenses emotional candor and domestic detail that the author's own social position would have suppressed.
Throughout the fifty-five day sea voyage the narrator repeatedly grieves a young daughter who died during the family's posting in Tosa and so cannot return home with them. Returning to the capital house, now decayed, the parent sees a pine tree sprung up where a child should have grown, and the contrast between the surviving plant and the lost child breaks the restraint the diary otherwise maintains.
At nearly every notable moment of the journey, departure, danger, memory, the travelers produce short poems, and the diary treats this as the natural human response to being moved. It judges the poems by whether they honestly answer the occasion rather than by technical polish, noting that even clumsy verses count when the feeling is real.
The diary measures the voyage not in distance covered but in waiting, weather, delay, and the moods these produce, so that stalled days at anchor get more attention than progress. Seen this way, a trip is a sequence of inner states triggered by external obstacles, and the landscape matters chiefly as a prompt for memory and longing.