Izuku is a very timid, reserved, and polite boy, frequently overreacting to abnormal situations with exaggerated expressions. Due to yeаrs of being looked down on by Katsuki for lacking a Quirk, he is initially portrayed as insecure, tearful, vulnerable, and non-expressive Izuku has immense, genuine compassion for people; he's shown that in dozens of ways besides his drive to be a professional hero. Insecure — but with a core of strength and good-heartedness that keeps him ahead of it.