A tough guy…

A character's eye fills the screen, revealing a red, spiral-patterned iris as the pupil contracts, followed by a close-up of a man's face contorted in shock and pain. The scene then cuts to a pair of hands adjusting a white shirt, a hand pulling at the collar of a blue uniform, and finally a wide shot of a classroom where a shirtless boy stands before a group of students, some of whom are looking at him with concern.