Zenkai (禅海)
Zenkai (1691 - 1774) was a Buddhist priest of the Sotoshu sect of Zen Buddhism in the middle of the Edo period. He was the son of a feudal retainer of Takada Domain in Echizen Province. His real name was Ichikuro FUKUHARA. Some record says his birth was in 1687.
His full Buddhist name was Shinnyoan Zenkai; he lived in Asakusa, Edo; his ancestors were said to be the Fukuhara clan of Takada Domain in Echigo Province; and he was a member of rokuju-rokubu (Buddhist pilgrim carrying 66 copies of the Lotus Sutra to be left at sites across Japan) of the Sotoshu sect.
He felt the absence of absolutes upon the death of his parents, entered the priesthood, went on pilgrimages to various parts of the country and obtained the Buddhist name, Zenkai, when he experienced tokudo (a rite to become a monk) in 1715. He was known as the creator of the Blue Tunnel in Yabakei Valley, Fuzen Province (today's Oita Prefecture).
When he paid a homage to Rakan-ji Temple, Bungo Province (today's Nakatsu City) during his pilgrimage, he learned that Aono-watari, a pier built on a cliff along a river, was so fragile and shaky that people and horses often fell down into the river and felt so sorry that he made a vow of building a path and came up with the idea of excavating for the path. In around 1730, he started excavation with the approval of the head of Nakatsu Domain in Buzen Province and completed the work in 1763, in about 30 years, with the help of local residents and the support of local domain lords in Kyushu. The tunnel was 6.06 meters in height, 9.09 meters in diameter and 308 bu (560 meters) in length.
According to a legend, after the tunnel was opened, people who used this tunnel paid a fee, and therefore this tunnel is said to be Japan's oldest toll road.
This story became a model of one of the works of Japanese novelist Kan KIKUCHI, "Onshu no Kanata ni" (Beyond Love and Hate). The murder episode depicted in this novel is a fiction created by the author Kikuchi; according to the novel, the main character killed his master, a direct retainer of the Tokugawa Shogunate, Saburobei NAKAGAWA, ran away with his master's concubine, became a robber while running a rest house at Torii Pass (Nagano Prefecture), but when he felt his sin, he went into priesthood, started excavation of a tunnel in expiation for his sin, and ended up working together with a son of Saburobei, who followed him seeking revenge, to complete the excavation.