Shingakkou: Noli me Tangere

Shingakkou - Noli me Tangere - tells a story of Michael Levi. His father, mother and younger sister were murdered by people who seem to be members of a satanic cult. Michael and his twin brother Gabriel (or Gabby) were students in a Seminary. They heard rumors that the cult members were in the same school, so they returned back there and with the help of their fellow students and friends tried to uncover the mystery surrounding their family's deaths. But some things were better left in the dark.

(Source: Shinmakoku Scanlations)