Battle of Dōmyōji On June 3 , 1615 the Eastern Army of Tokugawa Ieyasu and the Osaka Army of Toyotomi Hideyori clashed in battle at Dōmyōji ( 道明寺の戦い ; Dōmyōji no tatakai ) , Osaka . This battle was one of Japan ' s major historical battles between samurai forces . This battle was one of a number of battles that took place during the Summer Campaign of the Siege of Osaka that led up to the fall of Osaka to the forces of Tokugawa and the death of Toyotomi Hideyori . A vanguard force ahead of the Osaka Army was commanded by Gotō Mototsugu . He had with him a force of 2 , 800 samurai and his mission was to guard against the arrival of elements of The Eastern Army . The eastern border of Osaka is protected by a natural border known as the Ikoma Mountain Range . Gotō was given the task of guarding the area near Komatsu - yama , a hilly area located near one of very few mountain passes . This pass in the range is created by the Yamato - gawa river which runs just north of Komatsu - yama . He had planned to occupy the high ground provided by the slopes of Komatsuyama and prevent the enemy from freely entering the flat plains of Osaka that exist once past Komatsu - yama . The battle . On June 3 Gotō Mototsugu and his forces were at Dōmyōji , a low - lying section of land north of Komatsu - yama on the oppisite side of the Ishikawa river which is a tributary of the Yamatogawa river . In order to take their positions on Komatsuyama they would have to ford the Ishikawa river , as they are doing so scouts reported that the Eastern Army had exited the pass through the range and were moving up the southern slopes of Komatsuyama . At 4 : 00 AM Gotō Mototsugu and his samurai make a dash to Komatsu - yama in order to push the Tokugawa forces back . By 5 : 00 AM Gotō Mototsugu is forced back to the summit of Komatsu - yama by a strong attack by the enemy . All this time Gotō Mototsugu is awaiting the planned arrival of reinforcements which have been delayed by thick fog . Then at 10 : 00 AM Gotō Mototsugu is shot and commits ritual suicide . With his death his remaining samurai forces lost control of Komatsuyama and are forced to fight as they are pushed down the southern slope of Komatsu - yama and across the Iskikawa river . As the fog had cleared the Osaka Army forces on the southern side of the Ishikawa river had been revealed . Susukida Kanesuke lead the left flank of the Osaka Army . After advance Eastern Army sections cleared the Ishikawa and made their way up the gentle slope of Domyoji Susukida Kanesuke and his samurai fought them fiercely in an area next to Emperor Ingyo ' s massive tomb . Susukida Kanesuke who was in disgrace at the time fought valiantly and died in battle and in doing so redeemed his honor . Sanada Yukimura in command of the Osaka Army on the right of Susukida Kanesuke is taken on by Date Masamune in the area of Emperor Ōjin ' s Tomb and Konda Hachiman Shrine . This fight takes place at around 12 : 00 and by 5 : 00 PM Sanada Yukimura makes the decision to begin a retreat towards Osaka Castle having already lost two powerful commanders . Tokugawa Tadateru the sixth son of Tokugawa Ieyasu is given the order to pursue Sanada ' s force , but refuses . His refusal will later lead to his exile at Kōya - san . Sanada Yukimura and his army successfully disengage in retreat from the Eastern Army . Geographical notes . Whilst the geographic features of this battle remain the area referred to as Komatsu - yama has been renamed in later history to Tamate - yama . The pass through the range , the rivers and tombs of course remain giving any interested party the chance to visit and visualize this battle .