Sen is a young man with dark, shaggy hair, and dark eyes, which are rather thin and lazy-looking. He seems to have a modest athletic build, the same as most of his classmates, and a slight tan.
His hero costume appears to be a windbreaker with rings around the base of the neck and arms. Over this, he wears a large trench coat and gloves.
Sen is a stoic person who remains mostly calm and focused during 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.
Volume 22 mentions that he's rather belligerent in terms of personality and often gets dragged along in his friends' antics. Sen is also described as an "ikeman", having the appearance of a good-looking man. 
Gyrate (旋回 Senkai?): Sen's Quirk allows him to rotate any part of his body like a drill. The effects of Gyrate turn Sen's limbs into something akin to large rotary tools. This enhances his hand-to-hand combat abilities significantly.
Drill Gloves: Sen wears gloves with a spiral pattern on the fingers. These spirals act like a drill and cut into an enemy, thanks to his Gyrate quirk.
Battles & Events
- Sen likes cameras.
- Sen's name contains the kanji for "revolve" (回?), "field" (原?) and "rotation" (旋?).
- Sen's second English voice actor, Matt Shipman, also voices Inasa Yoarashi.
- Sen appears to be good friends with Kosei Tsuburaba, Hiryu Rin, and Yosetsu Awase. 
- ↑ My Hero Academia Manga: Chapter 29.
- ↑ My Hero Academia Manga: Chapter 26.
- ↑ My Hero Academia Manga: Chapter 203.
- ↑ My Hero Academia Manga: Vol. 22.
- ↑ My Hero Academia Manga: Vol. 21.