Long ago, in a time before Pokemon, the land known now as Olivine, was once known as Nippon. The land of Olivine isn't much different to Nippon. Their cities and towns barely changed in longer than anyone could seem to remember. As much as Olivine is a land that loves it's gods, so was Nippon. But Nippon wasn't always that way. There was a time where the demon Orochi was freed from his seal in the Moon Cave.
"What? How'd that happen?"
An idiot man didn't believe in the legends of Orochi and how he was sealed by the sword of the legendary Nagi, Tsukoyomi. Thus Orochi was freed. A curse fell upon the land of Nippon and the Guardian Sakura tree in Kamiki Village started to whither. It was in this time that the Sun Goddess Amaterasu appeared to save Nippon. She traveled across the land with her Celestial Envoy and healed the Guardian Saplings, restoring power to Sakuya and the Guardian Sakura tree.
Amaterasu soon defeated Orochi and he was once again sealed away. But evil still lurked in Nippon, so Amaterasu continued her quest to bring light to the land. After Amaterasu defeated the evil Yomi, she returned to the Celestial Plains. Although that wasn't the last time that she saved the land, the next time it was no longer called Nippon…
…
"That's it? You're not going to continue you're story? Really Isshana-san?"
I suppose I could tell you about the next time Ammy came to this land…