Kasugayama Castle

Katsugayama Castle (春日山城) is one of the Uesugi's known castles built in Echigo. Kenshin inherited it as a part of his Nagao family heritage and used it as his main dwelling. The Uesugi Manor, the office and residence of the Echigo-Uesugi Governor Norimasa Uesugi, once stood near the base of the castle.

After Kenshin's death, the castle grounds became one of the major battlegrounds for the civil war between his two potential heirs, Kagekatsu and Kagetora. Kagekatsu held himself within the castle, and Kagetora besieged it while stationing himself within the Uesugi Manor. This conflict is often called The Otate War (御館の乱, Otate no Ran), "Otate" being an archaic name for Uesugi Manor.

Koei's adaptations of the conflict mainly center on events that occurred near Katsugayama Castle.

Samurai Warriors
The castle siege for Katsugayama Castle often results in Kagetora's immediate demise in this series.

Players side with Kagekatsu's forces in Samurai Warriors Chronicles and Samurai Warriors 4. In both versions of the conflict, his forces have to flee from Katsugayama Castle due to a fire attack. Their goals are to rout the Hōjō and Date forces, and convince the Takeda forces to defect to corner Kagetora and Aya. Kotarō and his clones act as a major obstacle to the main camp defenses.

In the Chronicles version, Kagekatsu's forces make an additional effort to detain Norimasa before he flees. Kagetora leaves the Uesugi Manor and attempts to reach Sameoka Castle to regain a second wind. Aya acts as the last character that needs to be routed. The fourth title replaces Norimasa's retreat with Lady Hayakawa, Kai, and Kojūrō's appearances for their respective forces. Aya acts as a decoy for Kagetora's desperate last charge for Katsugayama Castle. She must be beaten in order to reach Kagetora in time.

Aya's story in Sengoku Musou 3: Moushouden allows players to fight for the Kagetora side of the conflict. Players are asked to keep morale high by protecting Kagetora from immediate threats. If they succeed, their next objective is to conquer the west to make way for the Hōjō reinforcements. Yukimura's charge towards the main camp occurs regardless if the player fails or succeeds this objective. When Yukimura and Kunoichi are routed, Nobunaga and the Oda army automatically enter the battlefield as third-party forces. Nobunaga's defeat causes the Oda to flee and is needed to trigger Kanetsugu's charge, which opens the gates for Kagekatsu's main camp. Kanetsugu attempts to stop the player's victory twice.

Nobunaga's Ambition
Nobunyaga no Yabou showcases this battle during the Bishamonten no Hata scenario. Players could read key events that occur for the conflict and fight against the dead to give their souls rest.