This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
A renga session gathers several poets in one room to build a single continuous poem none of them could write alone, and the rule that makes this work is narrower than it sounds: each poet responds only to the stanza immediately before their own, not to the sequence as a whole, so no participant needs to hold the whole developing poem in mind, only the last move made. A hundred-stanza sequence, the classic hyakuin length, can wander from a spring image to a lament to a comic aside and back again over its own length, each individual link locally coherent while the whole session has no single controlling intention behind it at all. The resulting poem belongs to the group in a way a solo-authored poem structurally cannot: no participant chose its overall shape, and no participant could have written the whole of it by themselves even if they had wanted to.