Sekigahara

The Battle of Sekigahara (関ケ原の戦い, Sekigahara no Tatakai) is largely considered to be one of the most decisive battles in the late Sengoku period. Essentially, it is a power struggle for the right to rule the land after Hideyoshi's death.

Samurai Warriors
There are many possible outcomes to this battle in Samurai Warriors 2. Every officer who participates in this battle for the Eastern Army starts by seizing the enemy's cannons. They can also protect Naomasa Ii and Masanori Fukushima as they perform an overzealous charge against Mitsunari; losing them will lower ally morale. Officers are also asked to guide Magobei Fuse to Mount Matsuo where Kobayakawa remains indecisive in a garrison. If the ploy succeeds, he will defect and the army will gain the winning edge in battle.

Generally, the Western Army officers will be given the chance to route Ieyasu's forces. Minor differences can occur in certain characters' story scenarios such as Yukimura, Nene, and Yoshihiro's dream stages. Musashi begins his story here as a warrior on the fallen Western side and has to fight for his survival. There's also the instance where Ieyasu also dies upon his defeat such as in Motochika's story mode.

Kessen
In Kessen, this battle will decide who lives or dies for the remainder of the game's campaigns. The concepts of the Western and Eastern army remain after the battle's conclusion. In the Tokugawa camp, the pre-battle cutscene dramatizes the former Toyotomi general's reasons for joining Ieyasu. Moments before the battle commences, Ieyasu sees a vision of Nobunaga bidding him to continue his legacy. Determined to win, Ieyasu draws out his sword and, whilst declaring his desire to rule, cleaves the mist enshrouding the battlefield. Scoring a victory in this battle acts as the first step for Ieyasu's path as shogun.

By contrast, the Western Army scenario touches on some of the generals' conflicting feelings regarding Mitsunari. Undeterred by news of betrayal amongst their ranks, Mitsunari marches into battle. He swears to protect the Toyotomi family and repay his debt to the late Hideyoshi. If Mitsunari wins this battle, he will pursue the fleeing Ieyasu with reinforcements from the Sanada troops. Losing any major battle after this will usually result in Mitsunari, Sakon, or Otani's deaths. Winning every battle for the Toyotomi side will secure their family's reign by Mitsunari's hand.

Depending on the actions of the player, the armies will fight at Sekigahara again as their final battle.

Saihai no Yukue
Sekigahara is the main setting for Saihai no Yukue. The player sees the game from Mitsunari's point of view which villainies Ieyasu. The story explores characters and famous events before the main confrontation.