In this world, Goddesses are real and are worshipped by the majority of the world. There are different kinds of Goddesses for everything — but there was one who can do anything.
She was an exception, a being who can be called supreme among the Goddesses, however, she was forgotten and soon was sealed because of some unknown circumstances.
How could a Goddess with exceptional prowess to every single thing—lose sovereignty? It's a mystery, indeed.