Ch.22 of Kamisama Hajimemashita
A man who calls himself the Dragon King (Ryuu-ou) appeared, saying he'd been waiting for Tomoe to step into water for hundreds of years. Ryuo made all the other humans faint, leaving only Tomoe and Nanami, claiming that Tomoe had a debt that he owed Ryuo. Tomoe saying he has no idea what he was talking about when Ryuo told him that 526 years ago, he ransacked Ryuo's castle and stole his right eye. He quickly captured Tomoe in a shell and left. However, Nanami grabbed on to the lip of the shell and followed him underwater, feeling guilty to let Tomoe go into the water. Out of breath, they resurfaced, Ryuo commenting on Nanami's stupidity. He gives her a check she must pay for his saving of her life but Nanami ignores it and asks him to give Tomoe back. Ryuo says that he would only return Tomoe if Nanami could get back the right eye which Tomoe had stolen in two days, which was basically impossible since even Ryuo had no idea what had happened to it. He explains his eyes were an elixir that granted powers to those who drank it. Meanwhile, in the hotel Kei and Ami are worried for Nanami and Tomoe but Mizuki assures them the they were okay. Nanami comes crawling in and asks Mizuki for the Time Rotation Incense Burner in order to get Ryuo's eye. Mizuki tells Nanami that Tomoe was lucky the she would go to such heights for him and that he was very envious. He asked Nanami if she had ever held such feeling about someone. He tells her it taboo but it must be okay since she was a god then sends her back in time, promising to go with her but only as a guide. She goes back, remembering Tomoe. She finally arrives in a snowy landscape. A figure appears, asking if she wanted a kazuki in exchange for the dragon eye Nanami possessed in her body. Mizuki calls to Nanami, the figure disappearing. Nanami tells him what happened and he says that it was the yokai Isohime. Nanami hurries to find Tomoe then sees him, a giant anemone chasing him, telling him to return the Dragon King's eye, which he burnt quickly. When he finishes, he sees Nanami, who was previously unable to believe that this was Tomoe, now knows that this was merely the person she loves still stuck in the darkness.