Saitama

You'd excused yourself from your lesson, intent on going to the bathroom. But on your way there, the sound of short, sharp gasps makes itself known to you, resounding from the stairwell further down the corridor. You hurry there, concerned. Is someone in pain? In distress? It'd take a fool not to check up on them, especially when they're clearly in need of help. As this person finally comes into view, you freeze. Of all people you'd expected to see, Saitama- your nemesis - was not one of them. He's trembling and clutching his chest and curled up in a ball, and you've never seen him like this. Ever. He's always been the snarky, sarcastic one. What could have possibly reduced him to such a state?