"The River-Merchant's Wife" begins with a picture of a childhood friendship. The speaker remembers a time when her "hair was still cut straight across [her] forehead"—that is, when she still had ruler-straight little-kid bangs. Back then, she recalls:
I played about the front gate, pulling flowers.
You came by on bamboo stilts, playing horse,
You walked about my seat, playing with blue plums.
The "you" in the speaker's apostrophe, readers can sense, must be an older child, a kid allowed to ramble around on stilts while the speaker is still confined to her family's front garden.
The speaker uses simple, direct language here, merely describing what she and this older kid used to do. The specific things she chooses to describe, though, paint a vivid emotional picture. The image of the older child "walk[ing] about" the speaker as she sits "pulling flowers," for instance, suggests that the older child is a bit of a show-off, in a sweet childish way, trying to impress the speaker with his stilt-walking and a tasty armful of "blue plums." That showing-off seems to have worked, too: the speaker remembers it well even now that she's older.
And take another look at the parallel structure in these lines:
I played about the front gate, pulling flowers.
You came by on bamboo stilts, playing horse,
You walked about my seat, playing with blue plums.
These circling repetitions mirror the way the older child circles the younger one—and suggest that these games happened more than once, that the speaker is describing not just one afternoon but a whole childhood of play. And so, the speaker says, "we went on living in the village of Chōkan": / Two small people, without dislike or suspicion."
That image of "small people, without dislike or suspicion" evokes a kind of innocence the speaker has grown beyond but remembers fondly. As "small people," she and her friend are getting ready to grow into big people who will know dislike and suspicion, whose hair is no longer cut in straight-across bangs.
In its first lines, then, the poem paints a picture of gentle, fond memories. The "you" the speaker addresses must be a person she still cares about—and perhaps a person for whom she still feels a flicker of the awe a younger kid feels for an older one.
These lines also give readers a peek at the speaker's world. Ezra Pound adapted this poem from an 8th-century work by the Chinese poet Li Bai (whom he credits here as "Li Po"), and the scene here—bamboo stilts, blue plums—suggests a picturesque, rural, long-ago China.