Ōtsu Castle

The Siege of Ōtsu Castle took place in 1600, concurrent with the battle of Sekigahara. Takatsugu Kyōgoku held Ōtsu castle for the Tokugawa, and commanded the garrison. This battle required a collaboration between Muneshige Tachibana and the Mori forces in order to force Takatsugu Kyugoku's surrender. However, in at the same time, Ieyasu Tokugawa won the battle of Sekigahara, assuring his control of all Japan and rendering the loss of Ōtsu ultimately insignificant.

Some records of the time indicate that the local inhabitants brought picnic boxes and gathered at Mii-dera on Mount Hiei to observe the battle.

Role in games
Ōtsu castle first appears in Samurai Warriors 3 and shares the same map as Oshi Castle. Both Muneshige and Yoshihiro Shimazu work with the undermanned western army in order to seize the castle. Playing it in one's story leads to the rival character attempting to hold off the enemy at the central garrison allowing the player to seize the castle in the meantime. As the castle is seized, Magoichi Saika plants an ambush in the castle and Kanbei Kuroda and Tadakatsu Honda arrive as reinforcements placing the main camp and Sakon Shima in considerable danger. Once the player doubles back to the main camp, defeating all enemy officers will win the battle. Unlike history, in this game the battle takes place well before Sekigahara, ensuring that Muneshige and Yoshihiro can arrive in time for the climatic battle in their respective stories.

Historical information
As Ishida Mitsunari gathered up supporting warlords, Ōtani Yoshitsugu called on Kyōgoku Takatsugu to follow him towards a rendezvous with Mitsunari. However, Takatsugu had previously pledged his loyalty to Ieyasu and the eastern army. As a result, Takatsugu lagged behind Yoshitsugu and instead quickly seized Ōtsu Castle in an effort to disrupt safe transportation between Echizen, Mino, and Ise. Takatsugu holed himself up in the castle with around 3,000 men, prepared for a long, drawn out siege.

Motoyasu led 15,000 western army forces against Takatsugu, setting up canons and firing into the fortress's thick walls. Tachibana Muneshige's forces led the forces skirmishing with the defending forces outside the wall and against the walls as the siege progressed. However, the Western forces were unable to force their way in and began seeking medication from Ōsaka, which was eventually agreed upon on the day Sekigahara was fought. Although part of the surrender required Takatsugu to retire as a monk, Ieyasu's victory allowed his to quickly return Takatsugu to the rank of daimyo.