Who he was
Evidence grade: Probable · Most likelyNobumoto served the Hosokawa, who held Buzen province from 1600. He kept Moji castle for them, on a hill above the strait between Kyushu and Honshu. The castle was closed in 1617. Its hill is now Mekari Park.
We know him mainly through the record his descendants put together about his life, finished in 1672. We have found no portrait of him and no birth year.
The duel across the water
Evidence grade: Traditional · Later accountsThe 1672 record tells the duel with Kojirō only to explain why Musashi needed Nobumoto's help. Both teachers agreed that no pupil would come. Kojirō came alone. Musashi's pupils came and hid.
Kojirō was struck down, then came back to life, and those pupils beat him to death. The record does not say what part Musashi had in it. When the news reached Kokura, a great many of Kojirō's pupils went to the island to kill Musashi.
Musashi at his gate
Evidence grade: Traditional · Later accountsMusashi fled to Moji and begged Nobumoto for help. Nobumoto took him into the castle, and Musashi came through unharmed.
Then Nobumoto sent him on to Bungo with a rider, Ishii Sannojō, and musketeers to guard the road. The record says he arrived without incident and was handed to "one called Munisai", most likely his father.
How we know
Evidence grade: Probable · Most likelyIt is the earliest account that names Kojirō, and the earliest that says he got up after the blow. Later accounts tell that part in other ways. It comes from a family with no stake in Kojirō, but it does need Musashi to be in danger, because the story is about Nobumoto saving him.
We read it through a modern reading text printed by Soeda town. We have not seen the manuscript. One modern writer gives his years at Moji as 1600 to 1617 and his death as 1624; we have not checked those against an original record. Episode 4 follows this record.