Rengoku ni Warau

Chapter 55: The Three Siblings from Purgatory, Reuniting in Oumi
Vol.9 Chapter 54: Iga's War, Quietly Reaching Its End
Vol.10 Chapter 56: A Friend, Betraying Their Friendship
Vol.9 Chapter 54: Iga's War, Quietly Reaching Its End
Vol.10 Chapter 56: A Friend, Betraying Their Friendship
The story is set 300 years before Donten ni Warau, during the Tensho Period. At Lake Biwa, the largest lake in Japan, the battle with Orochi ensued.