Steel Lady Nanase (鋼人七瀬, Kojin Nanase) is an urban legend of the vengeful spirit that haunts the Makurazaka town, based on the untimely death of idol Karin Nanase. She is later revealed actually not the ghost of Karin Nanase, but in fact, an imaginary creature created by Rikka Sakuragawa's powers.
She takes on the image of the idol Karin Nanase, the only physical difference being the gaping hole where her face should be. As a part of her ensemble, she carries a steel I-beam, similar to the one that smashed Karin Nanase's face and took her life.
Steel Lady Nanase was first brought into the public eye with the creation of the Steel Lady Nanase Wiki, an online site made by Rikka Sakuragawa. It slowly rose into infamy after a rise of sightings around the city.
She first appeared in a faraway city named Makurazaka. The rumor is that night after night she manifests, she crawled out from under the pile of girders as if being reborn. She wears the same outfit she did when she was an idol lugging around the same steel beam that crushed her face.
Supernatural Strength: Steel Lady Nanase's inhuman strength makes her a deadly combatant, outmatched both Kotoko Iwanaga and Saki Yumihara. She is able to 'kill' Kuro Sakuragawa multiple times if it wasn't for Kuro's immortality. She fights with the steel beam that she always carries as her main weapon.
Intangibility: Despite visible to the naked eye, she can't be touched by ordinary humans for some reason. This has proven when Saki Yumihara and Terada tried to land an attack on her, only to pass through her body. However, those who have spiritual power or are connected with the yokai and spectres such as Kotoko Iwanaga and Kuro Sakuragawa, are able to casually hit her.
Immortality: She possesses incredibly high level of endurance, able to ignore most injuries. In fact, however she is immortal since she exists because of human thought. Thus, as long as there are humans supplying thoughts of her existence, she remains effectively unkillable, hence her life lies not within her body but within the countless desires that have given her form its flesh.