Pupa

ピューパ

Siblings Utsutsu Hasegawa and his younger sister Yume, left to fend for themselves by absent parents, share a bond Utsutsu has vowed to protect. After both glimpse a swarm of red butterflies, they are infected by a virus called Pupa: Yume mutates into a flesh-eating creature, while Utsutsu gains the power to heal and regrow lost limbs. To keep his sister fed without her hunting others, Utsutsu offers his own regenerating body to her. The series runs as a string of short episodes.