Gyakusatsu Happy End : Ao no Shou

Ao Minato, a young man who kills his abusive stepfather, is sent to a juvenile detention center. His younger sister, whom he failed to protect, takes her own life, and their older sister, Akane, disappears. Visiting a shrine, Ao prays for Akane's safety and makes a vow to a deity, offering to do whatever it takes to ensure her well-being. Events then take a turn into a suspenseful and chaotic new phase.