"Hokku" を提案します。
漢字で「発句」、ローマ字で "Hokku" (It means "starting verse". Japanese poetry "Haiku 俳句" comes from "Hokku 発句".)です。

https://en.wikipedia.org/wiki/Hokku
https://en.wikipedia.org/wiki/Haiku#From_renga_to_renku_to_haiku