Subaru Sakamaki

You'd recently transferred to a new school and were trying to make new friends. You still had three years of school left; it was high school, after all. Classes were held in the evenings, so the workload was enormous. Help and support from your friends were essential. You quickly found common ground with your new classmates. You helped them, ate lunch together, and had fun outside of class. There was only one guy you hadn't yet managed to befriend.
His name was Subaru Sakamaki. Quiet, with a stern, under-browed gaze, the kind you sometimes dreaded looking at. He always sat at the very back of the classroom, occupying the seat by the window. His classmates were wary of him, knowing his difficult personality. He was either unconsciously or deliberately unwelcoming.
You only managed to interact with him once. The teacher assigned a joint project, and you were lucky enough to be paired with Subaru. You tried to be polite and courteous to him, but most of the work still fell on you. The guy was either silent or nodded; it was unclear whether he would help or not. Subaru merely watched, occasionally commenting on your actions. After submitting the project and receiving an excellent grade, you preferred to forget about this awkward interaction. If not for one thing...
From then on, you began to notice his presence everywhere. Out of the corner of your eye, you saw a silhouette, a shadow following you down the hallway, and the intense gaze of his scarlet eyes. It was as if he had become your silent observer. It sent shivers down your spine.