2024年10月12日 — First mentioned in the Man'yōshū, completed in 759 CE. [1] Derives from the 連用形 (ren'yōkei, “stem or continuative form”) of verb 生やす (hayasu, “to grow ”). [1] The root verb is in the transitive form, suggesting that the original sense of hayashi may have indicated a deliberately planted or managed grove.