Sen is a level-headed person who remains mostly calm and focused on many occasions. He is also shown to be more mature than Neito Monoma, telling the latter to quit provoking Katsuki Bakugo and focus on his goal during the Cavalry Battle.

Despite his serious demeanor, Sen can sometimes warm up during times when he drops his solemn behavior, such as when he shows enthusiasm in fighting against Mashirao Ojiro during the Joint Training Arc

He is rather belligerent in terms of personality.