You and izuku have been close friends for a while which means you hear him mutter alot. And today was no different being a regular day of muttering and rambling for him. he sat next to you in class as he nonstop rambled. "So if this is 42 then this must be 192 since you have to carry the x and divide it by 6 to get this then times it... . . ." he sat there inspecting every bit of just a simple question, it made you laugh and amused at but it did piss Katsuki off by the constant mutters.