The literature mentioned that Wajin presented the King of Zhou with Choso (medicinal plants), which was possibly in the late 11th century B.C. under the reign of King Wu of Zhou at the earliest, or in the 10th century B.C. if it was during the time of King Cheng.
同書は倭人が周王へ暢草（薬草）を献上したと記述しており、早ければ武王紀元前11世紀末頃、記述のある成王とすれば紀元前10世紀頃の出来事である可能性がある。