The play "Hachijin Shugo no Honjô" was originally written for the puppet theater (Bunraku) and staged for the first time in the 9th lunar month of 1807 in Ôsaka. It was quickly adapted for Kabuki by the sakusha Nagawa Kunisuke, Nagawa Tokusuke I and Ichioka Washichi I and staged for the first time the following year, in the 3rd lunar month of 1808 in Kyôto at the Kitagawa no Shibai [casting]. In order to avoid the Shogunate censorship, the identity of all historical characters were disguised (more or less lightly):

The "Kosui Gozabune" scene (literally 'The Magnificent Boat on the Lake') is the 4th act of "Hachijin Shugo no Honjô", which was originally made up of 11 acts.

Satô Masakiyo stands as one of the few remaining loyalists of the fallen regime, positioning himself as the guardian of Oda Haruwaka, the child heir of his former lord. Yet, he faces a formidable adversary in Hôjô Tokimasa. In the preceding scene, Tokimasa commands his retainer, Mori Sanzaemon, to present poisoned sake (dokushu) to Masakiyo. Sensing Masakiyo's awareness of the danger, Sanzaemon consumes the toxic concoction himself, prompting Masakiyo to follow suit.

The poison takes its time to act on Masakiyo, who then departs and boards his ship bound for Azuchi Castle. As the scene unfolds, a majestic ship fills the stage, with Masakiyo adorned in resplendent robes, accompanied by Hinaginu, the betrothed of his son. The ship sails on Lake Biwa ^[2]. Unbeknownst to her, Hinaginu is the daughter of Mori Sanzaemon, oblivious to the political rift between her father and Masakiyo. She remains unaware, like Masakiyo, of her father's poisoned state, possibly succumbed by now.

A small boat approaches, carrying Todoroki Gunji, a man loyal to Tokimasa, feigning to be a messenger from the lord. He is astonished to find Masakiyo in apparent good health and swiftly retreats. Another "messenger" soon follows, secretly a spy sent to assess Masakiyo's condition. Bewildered by Masakiyo's well-being, he too departs after leaving behind a large chest as a "gift."

Hinaginu, puzzled by the envoys' odd behavior, finds solace in Masakiyo's reassurance, and continues playing the koto upon his request. Sensing the poison coursing through his veins, Masakiyo summons his strength to pry open the chest, confirming his suspicions as a spy emerges. In a swift action, Masakiyo thwarts the would-be assassin, safeguarding himself and his charge.

[1] The title "Eight Battle Arrays to Protect Honjô Castle" came from osakaprints.com.

[2] Lake Biwa or the Yodo River, depending on the production.

The actors Ogino Senjo and Jitsukawa Gakujûrô II playing the roles of Hinaginu and Satô Masakiyo in the "Gozabune" scene of the drama "Hachijin Shugo no Honjô", which was staged in the 3rd lunar month of 1866 at the Naka no Shibai (print made by Nakai Yoshitaki)