D_Cide Traumerei the Animation (2021)

S1E11 Recollection

Ryuhei's best friend, Murase, was distributing Somnium Drops to the other students nearby. Just as Ryuhei starts to feel the sting of betrayal, a masked figure from the cult emerges and swiftly takes him down with one powerful strike. Stunned by the sheer strength of his attacker, Ryuhei reflects on his memories of his late brother, Junpei, who had fallen victim to this man. With Rando’s insights ringing in his ears, Ryuhei realizes that his brother had ties to Troy Merai.