Composer: Yasuharu Takanashi/高梨 康治
This is my favorite anime of all time, a hidden gem and such a tragic anime. Most of the ost are on point, give you the most accurate emotion for the scene, hands down.
Edit: Song is in E minor, my bad
Sheet: https://sheet.host/sheet/kBsTeL
MAG.MOE - The MAG, The MOE.