The 大坂夏の陣 (Osaka Natsu no Jin) — the Osaka Summer Campaign of 1615 — was the Tokugawa clan's final reckoning with the last dynasty that could challenge them. The Winter Campaign of 1614 had ended in a negotiated ceasefire, a truce that 徳川家康 (Tokugawa Ieyasu) used to fill in Osaka Castle's outer moats, stripping the fortress of the defenses that had made it nearly impregnable. When the armies returned in 1615, 大坂城 (Osaka Castle) stood far more exposed. Everyone on both sides understood this would be the end.

The Osaka strategy called for its commanders to strike Tokugawa columns while they were still on the march, before the encirclement could close. The defense would have to be fought on the roads, not behind walls. Multiple engagements were planned simultaneously across different approach routes. The road through 大和 (Yamato) Province from the south was assigned to a strike force led by 後藤基次 (Goto Mototsugu) — known by his common name 後藤又兵衛 (Goto Matabe) — age 50, a veteran of the most brutal campaigns of the 戦国時代 (Sengoku Jidai), the Age of Warring States.

Goto departed the 平野 (Hirano) district at midnight, leading approximately 2,800 samurai south through the darkness along the old roads to reach 道明寺 (Domyoji) before dawn. The plan required him to hold the crossroads until the rest of the southern army — including 真田信繁 (Sanada Nobushige)'s division — arrived to form a unified front. What the plan could not account for was the 霧 (kiri).

A thick morning fog settled over the 大和 (Yamato) lowlands before sunrise. In the murk, entire divisions lost contact with each other. Commanders shouted but could not be found. The columns following behind Goto scattered without direction. He arrived at 道明寺 (Domyoji) alone: 2,800 men against the forward elements of an eastern army numbering approximately 23,000 — a force nearly nine times his size, under the supreme command of 徳川家康 (Tokugawa Ieyasu) himself, with 伊達政宗 (Date Masamune), the famous one-eyed lord of the north, commanding a major division.

The rational choice was retreat. Goto chose to hold. He planted his battle banner among the ancient 古墳 (kofun) — burial mounds — that dotted the flat ground near 誉田八幡宮 (Konda Hachimangu) shrine, and ordered his men to fight. By all accounts his samurai acquitted themselves magnificently. Goto personally is said to have dispatched somewhere between 70 and 80 enemies before a 鉄砲 (teppo) musket ball struck him down. Wounded too severely to stand, he performed 切腹 (seppuku) in the field at approximately ten o'clock. 薄田兼相 (Susukida Kanesuke), arriving later with more Osaka vanguard troops, was also killed — fighting with his long sword until he was cut down.

By the time 真田信繁 (Sanada Nobushige) arrived with his famous 赤備え (akabusho) — red-armored troops — the fog had finally lifted. From roughly noon until five in the afternoon, Nobushige's forces engaged the vanguard of 伊達政宗 (Date Masamune)'s army in the landscape of enormous earthwork tombs near 応神天皇陵 (Emperor Ojin's Tomb), one of the largest 古墳 (kofun) in the world by area — a battlefield literally fought in the shadow of the ancient dead. By late afternoon, with two major commanders already lost and the eastern army pressing relentlessly, Nobushige ordered a retreat toward 大坂城 (Osaka Castle). The Tokugawa forces did not pursue.

The cost of 道明寺 (Domyoji) was not measured in ground. The Tokugawa eastern army advanced; the Osaka southern force fell back. But the true cost was Goto himself — an irreplaceable combat veteran whose death left the Toyotomi side without its most experienced tactical mind. The next morning, June 3, the climactic 天王寺 (Tennoji) battle would be fought. The Osaka forces would enter it already weakened, already demoralized, already short of their best commanders. 大坂城 (Osaka Castle) fell on June 4. 豊臣秀頼 (Toyotomi Hideyori) and his mother 淀殿 (Yodo-dono) committed suicide inside the burning castle. The 豊臣 (Toyotomi) clan was extinguished. The 霧 (kiri) of June 2 had claimed more than one man's life.