Tsuyu is a straightforward and aloof individual who always speaks bluntly from her mind and what she thinks about others. Tsuyu prefers to be called "Tsu", but only by people she views as friends.[1] She commonly refers to everyone with the honorific "-chan", save for teachers and other authority figures.

Tsuyu's parents were always busy at work, requiring her to become the caretaker of her two younger siblings at a young age. Under these circumstances, Tsuyu grew into a highly mature and responsible individual who could divide her attention between school and home duties without letting one intervene with the other. This also means that Tsuyu knows how to lead and look after people, keeping them safe and at ease if they don't feel so. She has strong morals, goals, and principles and is willing to oppose her friends to defend them from decisions she considers rash. When several members of Class 1-A agreed to rescue Katsuki Bakugo after the Vanguard Action Squad Invasion, Tsuyu was the most outspoken against it, asserting that acting on their emotions and breaking the law to rescue him made them essentially the same as villains.

Tsuyu is noticeably calm and collected, being able to stay levelheaded and focused even during the most stressful situations. An honor student since middle school, Tsuyu has great judgment, can communicate her intentions easily, and is rarely moved by emotion, making her an incredibly dependable ally who's capable of covering for a partner's weaknesses. For those reasons, Recovery Girl describes her as a "perfect pillar of emotional support".[3] However, even Tsuyu has limits when it comes to staying composed, having broken down in despair or heartbreak a few times. Her words may also come off as unintentionally harsh thanks to her blunt honesty, resulting in her feeling guilty and regretful when she speaks out against her friends.