Obusuma Saburō, once a samurai retainer and jitō manor steward, was exiled to Tsushima Island for attacking and murdering his brother to seize the family legacy. His banishment places him among prisoners reinforcing Tsushima’s defenses against the impending Mongol invasion. Unlike fellow exiles committed to the island’s defense, he questions resistance’s value and actively doubts repelling the Mongol forces. This skepticism drives his willingness to abandon defensive efforts. He attempts negotiation or alignment with the invading Mongol army, viewing surrender or collaboration as a pragmatic survival path. His actions stem from opportunism and self-preservation amid overwhelming odds.