Tokyo Ghoul fanfic.

Ghouls have lived about the humans for decades, eating humans to survive or starving to death for refusing to eat.
Ghouls vs Ghouls, Ghouls vs Humans.
Riko despises those who eat humans, for her family are humans. She was human at birth but because she was dying from a heart failure at a young age. Her aunt requested her heart was given to her niece. It worked. Her parents knew of what her aunt was, and what it did to Riko. So they fed her, the only thing they could. Humans. Dead of course. Her mother worked in the morgue. So it worked perfectly for a few years.
She could control her hunger for human very well. Until one day, she came home to find people surrounded around her home. She smelled blood. She saw the bodies of her family, in body bags.
"Let this be a lesson to those harboring ghouls. We will find you and you will be killed".