Mahiru Hīragi of Owari no Seraph

Mahiru Hīragi is the love interest and demon weapon of Guren Ichinose.
She is the main female character in the light novel series, Seraph of the End: Guren Ichinose: Catastrophe at Sixteen. She was the next successor of the Hīragi Family. She stole Krul's brother Asura from her and used him as her own demon weapon. She eventually turned into a demon and was sealed within Guren's weapon, becoming a Cursed Gear called Mahiru-no-Yo.

Mahiru has long blueish-gray hair with a front fringe and amber eyes; after becoming a demon, she has red eyes and fangs. In the anime, her hair has more of a lavender color. Unlike her younger sister, Shinoa Hīragi, she has a taller, well-developed figure.

When he was ten years old, Shinya had been selected by the Hīragi family to be the potential mate for Mahiru, and he was adopted into their family to this end. This was a plan by the Hīragi to keep their bloodline strong. However, when Shinya and Mahiru first met she told him she wouldn't fall in love with him as she already had someone. Had she openly stated to her family she didn't want Shinya, they would have disposed of him; and she wasn't allowed to be with Guren, whom she loved. For these reasons, they both agreed Shinya would be her cover-up fiancé until she could be with the person she loved.