The Western Forces (the Toyotomis) thought that, if the Eastern Forces (the Tokugawas) would come from the south, the decisive battle should be done at Tennoji.
In fact the Eastern Forces started from Kyoto toward Yamato, which is located in the south of the Osaka Castle.

Since it would result in the defeat of the Western Forces to have the Castle be besieged by the Eastern Forces, there was no way but going out of the Castle to fight against the Eastern Forces.

It was he, Matabei Mototsugu Goto, to insist on that the battle should be carried out at steep mountainous places near the borders of Yamato and Kawachi in order to intercept the large number of Eastern Forces skillful in a field battle with the small number of Western Forces.
But his plan was different from that of Yukimura Sanada and others.
Matabei had to spare his army to comply with the others' plan.

In the morning May 6, l615, when the army of Matabei Goto arrived at Domyoji, he was told that the Eastern Forces had already formed a splendid battle array at Kokubunji after having crossed the borders.

Upon hearing it Matabei ordered the army to start attacking at once.
This was the beginning of the Battle of Osaka in Summber.

The offensive and defensive battles at Mount Komatsu lasted for several hours.
The Matabei's army beated off the enemy's attack once, but they were in a precarious state as the enemy was far superior to them in number.

At last Matabei was shot in the chest by a bullet of the enemy of Date army.
He no longer had the ability to fight and killed himslef.