The extra boss of Mountain of Faith and god of the Moriya Shrine. Although, she said the shrine wasn't exactly hers (she mentioned it in both Reimu's and Marisa's story) saying it was officially Kanako's because she was beaten by her and had to relinquish control of the Shrine, willingly at that.
In Subterranean Animism, Suwako appeared in Reimu and Yukari's Scenario revealing an industrial revolution project by Kanako that caused Reimu to get mad for being sent to the Hell of Blazing Fires.
It is revealed that during ancient times, Suwako was a ruler of a small kingdom and controlled the Mishaguji, who were curse gods that had obtained enormous amounts of faith, cursing birth, harvests, militaries, and many other things. Only Suwako was able tame them. However, gods from the Yamato (Ancient Japan) invaded her kingdom, saying that they were going to unify all the kingdoms to create a single country known as Japan. Unwilling to let this happen, Suwako resisted and fought with the finest steel weapons of the time. However, Kanako held out a thin vine, and Suwako's large steel arsenal instantly rusted away. Suwako realized the difference in their divine powers and her defeat; she valiantly forfeited and relinquished her kingdom. It is said that her only direct descendant was Sanae, although Sanae didn't even know it until the events of Subterranean Animism.