Chapter 100 is one hundredth chapter of Volume 17.
Nanami recalls the time she first met Tomoe, how afraid and hateful she was of him. But just as she came to like him, his time ran out. Tomoe had waited 500 years for her and Nanami resolves not to make him wait any longer. She falls from the sky and immediately sees Mikage Shrine. She spots Mikage and hugs him in relief, telling him she'd found a way to break Tomoe's curse. Mikage only looks at her and ask who she was. Nanami is taken aback and says she was Nanami Momozono, the one he entrusted his shrine to. She suddenly notices how pretty Mikage Shrine was and realizes she still was not it her time. But before she leaves, Mikage grabs her arm and asks if she can truly save Tomoe.
Back in present Mikage Shrine, Mizuki finds the guests Ryuo, Himemiko, and Kotarou sleeping and complains to Mikage that everyone was so careless when if Nanami was out working hard on her own. He asks if Mikage was even worrying for Tomoe because Mikage always look so carefree and unworried, to the point he even left Mikage Shrine for 20 years. Mikage puts his pointer finger on Mizuki's lips and tells him that ever since he made Tomoe his familiar, he'd been worrying about him. He says that Tomoe had a debt to pay, the curse a bomb ready to kill him at any given time. Even Mikage did not know what to do. But then twenty years ago, he met a future Nanami, giving him the clue that she was the key to saving Tomoe.Suddenly there was a loud burst and Nanami came crashing through the door. Mikage asks her if she'd found the cure for Tomoe's curse. She says 'yes' and Mikage smiles and quietly asks Tomoe to wait just a little bit longer.
Within the mirror, Tomoe hears someone calling his name. He thinks its Nanami, then Yukiji, but then decides it wasn't possible since she died a long time ago. He hears Mikage's voice asking him to come out. He tells him that at this moment, Nanami was retrieving the the token of their contract.
On the night fog carriage, Nanami hovers over Ontake Mountain and spot a place that was familiar to her. She drops down and land on a branch. She tells Mizuki that what she was looking for was just below her and to get out of the carriage and get it.
Tomoe panics, unable to believe what Nanami was doing. Mikage asks again for him to come out because if he could have the item, the curse would be lifted. Tomoe only says that Nanami wouldn't be able to save him because human are weak. He didn't want anything to do with them anymore. Mikage tells him he didn't understand humans and asks if he remembered the baby Yukiji had. Tomoe tells him it probably just died. Mikage tells him that actually, it lived and grew up and had a child of her own. That child also grew up the same way and continued all the way down to Nanami. He tells him that humans were not weak but rather, it was Tomoe who was in danger now. She asks him again to come out but suddenly Nanami appears behind him and hands Tomoe the hairpin, saying that Tomoe had promised to marry her. Tomoe recalls that day and reaches for her, catching her in his arms. Nanami looks at him face and is relieved to see that the marks are gone. She leans in closer and asks Tomoe who she was. Tomoe kisses her and says she was Nanami. Nanami smiles and promises herself that from now on, she would always say how much she loved Tomoe.