A certificate remains of the Tori-ryu School that 'Miyamoto Muninosuke Fujiwara Kazuma' gave a vassal of the Hosokawa family, Kanjuro TOMOOKA (in the original, Muninosuke '無二助' is written as '无二助', '无' is the same kanji character as '無'); if 'Muninosuke MIYAMOTO' were identical with 'Muni SHINMEN' (Musashi's father, according to "Kokura Hibun"), Muni is considered to have known the Hosokawa family before the duel.
宮本無（原文は無の異字体の无）二助藤原一真が慶長12年（1607年）細川家家臣友岡勘十郎に授けた当理流の免許状が現存することから、宮本無二助を新免無二と同一人物であると考えるなら、舟島での試合以前から新免無二と細川家の結びつきが深かったと推察する事ができる。