Amaterasu will find herself inside a strange version of Kamiki Village. Head down to the village to speak with the residents, only for them to attack her. Continue to where Susano's hut is and look for the sleeping hero behind it. Give him a good headbutt to find out that it's not Susano, but rather Nagi. It is then revealed that the Spirit Gate has sent Amaterasu 100 years in the past.
With Nagi woken up, he will challenge Amaterasu to a duel as per legend. Battle him, but Amaterasu will accidentally knock him unconscious. With Nagi knocked out, Amaterasu has to make herr way to the sake house to find Nami bathing in the waters. She has to slowly walk up to the sacrificial robe that is on the ground behind her, grab it and then quietly escape to avoid detection. Once she has the robe, return to Nagi to dress him up and put him on her back. She now needs to make her way to the Moon Cave by way of Shinshu Field.
Though Shinshu Field looks very similar, it is occupied by demons. Head toward the Moon Cave. Just before entering the Moon Cave, Amaterasu will be interrupted by another demon, the Dogu. After they are defeated, head into the Moon Cave to engage in another battle with Orochi.