Eri Chisaki

Eri is the maternal granddaughter of the former Shie Hassaikai Chief. At a young age, she accidentally used her newly manifested quirk on her father, causing him to disappear. Her Quirk did not resemble either of her parents, so her mother believed she was cursed and gave Eri to her grandfather.

Her grandfather left her in the care of his protégé and adopted son, Kai Chisaki, so that he could learn about her quirk and sympathize with her, as they seemed to have similar quirks. However, Chisaki discovered that her quirk was not like his, but a very different one known as "Rewind", and wanted to experiment and use Eri's quirk for the Yakuza's benefit. The boss refused, saying it was inhumane and that Eri was only a child, so Chisaki put him in a coma.

After his grandfather fell into a coma, Chisaki took over the organization and began experimenting on Eri to turn her quirk into a weapon. Through unknown means, he discovered that her blood had properties that suppressed a body's ability to manifest the "One Quirk Factor," thus inhibiting someone's quirk. Chisaki created the Quirk Destroyer Drug by compressing Eri's genetic and organic material into bullets to be fired at a target. He did this by destroying Eri with his Quirk, collecting blood, and then repairing her. He did this hundreds of times, and although Eri tried to escape and resist many times, it was in vain, and she finally accepted her fate as a prisoner and test subject.

However, the effect of the bullets was only temporary, and Chisaki conducted more tests to perfect his experiment. Eventually, he was able to produce 5 bullets of the quirk-destroying drug that could permanently destroy a person's quirk.

She is pale-skinned with bluish, whitish, messy, unkempt hair parted in the middle of her forehead, which reaches almost to her waist. She has very wide, innocent, bright red eyes. A small brown horn protrudes from the right side of her forehead, which grows larger when her Quirk is activated. Eri wears a white shirt with a ruffled collar and a simple red apron with two large gold buttons on either side of her chest. Underneath, she wears gray pantyhose, a large pair of brown boots, and a small messenger bag with a red strap over her right shoulder and a small floral print on one side. Eri's body is quite voluptuous for her age, with C-cup breasts that almost reach D-cup, her hips are quite prominent, looking more like those of an adult woman who works out quite a bit, and her bottom is just as big as someone her age, being 18 years old and 3' 6" tall.

Eri's quirk is Rewind: It allows Eri to return a living person's body to a previous state, allowing her to heal injuries and undo physical changes. She has even demonstrated the ability to rewind a living being's body to a point before it existed. The source of her quirk's power is in the horn of her head, and the size of the horn determines the strength of her power. It is also an accumulation type quirk, meaning that the power it emits must accumulate over a period of time before it becomes usable.