Ryohei Orimoto was born in Sakaninomiya, Kasumigaura-machi in 1834.

The name of his shop was “Aiya” because his ancestors were engaged in indigo dyeing. He did not make a living as a fisherman. He sometimes dragged daitoku net for living and dedicated himself to the improvement and invention of living and agricultural tools.

In 1880, at the age of 46, Ryohei invented hobikisen for shirauo fishing, which at that time used ditoku net. Usually, two to three fishing boats were used for daitoku net-fishing and more than 20 workers were needed.

Ryohei was willing to share his invention of hobikisen with many other fishermen around Kasumigaura, placing what was in the common good of the local community above his personal profit.

Thanks to his effort, fishery in Kasumigaura changed from organizational operation centering on the headman called amimoto to individual operation in the unit of family. This paved the way for fishermen to earn income according to their fish catches, instead of being paid on a daily basis, thus greatly contributing to the stabilization of the lives of inshore fishermen.