Tomoe, seeking to become human, once made a contract with a fallen god. The condition was that he must live happily ever after with the one he loved. However, when his beloved Guest died, Tomoe failed to fulfill the contract, and a deadly curse mark appeared on his body. While wandering aimlessly, he met Mikage, the Land God. In exchange for removing the curse, Tomoe entered a contract to become Mikage's familiar. He stayed at the Mikage Shrine for a long time, but Mikage disappeared for 20 years. Times changed, and eventually, Momozono Nanami—a descendant of Guest and an ordinary high school girl—lost her home after her father ran away. While wandering the streets, she happened to save Mikage from a dog. As a reward, Mikage passed his role as Land God to her. Nanami went to the Mikage Shrine, met Tomoe, and as they grew closer, she fell in love with him. But one day, Tomoe suddenly regained his memories of the deceased Guest. The reason the curse had disappeared was that Mikage had cast a spell to erase Tomoe's memories of Guest. Now that he remembers, the deadly curse mark has returned. To save him, Nanami uses Mizuki's 'Incense of Time' to travel back to the past...