While it’s hard to pinpoint exactly when Japanese people started eating seaweed salad, we do know that Japan has a long history of preparing these sea vegetables. As Japanese seaweed education company Riken Vitamin explains, there is some evidence that wakame sushi has been eaten in the region since the Jomon period (6000-300 BC). In fact, when pottery from that era was found at the Kameoka ruins, it is said that the remains of wakame were also found.
By 701 BC, it appears that seaweed had become quite valuable to the Japanese. According to Hiroya, it was the year that a Japanese law called the Taiho Law Code stipulated that people could pay taxes in the form of seaweed. Nori is actually one of the main types of seaweed eligible for payment, although nori is also listed. Due to their popularity among the Japanese elite, these sea vegetables were considered valuable at the time.
Interestingly, at the same time, references to seaweed began to appear in Japanese poetry. The text Manyoshu, written in the 8th century, discusses this composition in a poetic manner. One poem even discusses this ingredient as a metaphor for survival and sustenance, reading, “Catch this short life / I live on seaweed / I’m soaked by the waves / Gathered on the island of Ilag.”