This trio of students attended First Shibuya High School, they are unnamed characters in the Seraph of the End: Guren Ichinose: Catastrophe at Sixteen manga. Even though a month ago there was an assault on the school in which over half the students were killed, they still collectively decided to pick on Guren Ichinose.
All three were male, and wore the same uniform. This was a buttoned, long-sleeved, dark colored jacket with a pentagram design emblazoned on the left chest area. One member had dark colored hair with it generally parted in the center of his forehead. A second member had his fringe trimmed almost straight across. The third youth had lighter colored, and messier styled hair.
Sneering and smirking at someone they perceived as inferior to them was the key observable trait they each had. As well as laughing at him together, they also saw it fit to assail Guren three on one.
Upon locating Guren seated on the ground, after Mito Jūjō and Norito Goshi had previously moved on their way, they spoke audibly how that the Ichinose scum was lazing about. Apparently they did not witness Mito pushing him over previously, yet a remark from another on how about Guren be their opponent this time may mean they did. Turning to Shinya Hīragi who approaches on how if they are going to bully the weak, they should not bully something like that, the three youths head elsewhere when advised to get back to their training.
They look down on, hassle and then resort to striking Guren who is regarded by students and faculty members alike as being from an inferior house and so warranting contempt.
Likely aware of who he is by reputation, or from other students mentioning his name, without a second thought they followed the direction of this adopted member of the Hiragi family, not because he was supposedly taking over the bullying, rather due to his title. One member addresses him as sir.