Hummingbird Monster

Rion and Kotone never wanted a life of fighting and death, but it's what they got after a freak run-in with a Hollow. Kisuke Urahara saves them and tosses them into an unforgiving Soul Society and Soul Reaper Academy where Rion falls head over heels for Toshiro. Kotone only gets more and more jealous as time goes on and snaps when she awakes after a 5-year coma hungry for blood.