Great Suwa War

Suwako Moriya came to Gensokyo from the outside world and is one of the gods enshrined at Moriya Shrine. She is the shrine's original god and Sanae Kochiya's ancestor.

Kanako Yasaka came to Gensokyo from the outside world and is one of the gods enshrined at Moriya Shrine. Previously, she was a god of wind and rain but is now a mountain god. On the surface, it appears she is the current god of Moriya Shrine.

One of Suwako's Spell Cards is named "Suwa War~ Native Myth vs Central Myth." It's said the attack is a recreation of Suwako's lived experience during the war, but she has never confirmed that to be true.

There once was a god that ruled over a kingdom. But one day, that kingdom was attacked by another god. The aggressor sought to unite all the scattered kingdoms into one nation Japan. The existing ruler used their advanced iron weaponry to stave off their foe, but they were outmatched. Their weapons were deadly, but the aggressor had the power to make them rust by waving vines. The existing ruler was defeated and handed over rule of the kingdom.

Though the war had ended, the tale had not. Despite their defeat, the kingdom's people refused to accept their new ruler. Even though they were the victor, the aggressor gave up their attempts to make the kingdom their own and joined together with the former ruler to call upon a different god, Moriya. The aggressor had Moriya run the kingdom while maintaining the title of "ruler" for themself. The aggressor has ruled in secret as a mountain god ever since.