Height: 170 cm

He is the charismatic president of the student council of Katagiri Senior High School who is enrolled in class 3-3, the childhood friend of Kyouko Hori and the boyfriend of Remi Ayasaki.

Sengoku is a rather shy boy who gets embarrassed easily and he is a very wimpy where the slightest thing will make him cower in fear, especially things to do with horror or insects. Sengoku is very smart and serious, normally ranked #1 in the school (and #2 in phys ed). He enjoys reading and has an incredible level of concentration while doing so, the point of ignoring everything else going around him.

He is generally not very expressive with his emotions. The sole exception is his anger or irritation, which he shows all the time as he is the Student Councils President. Even though he makes threats and gets angry towards those breaking the rules, he doesn't actually like doing so.

Sengoku is very insecure when it comes to his body. Thinking his slender body is embarrassing and always refusing to show it in various occasions, even going as far as to make up extravagant lies to get out of it. He wears multiple layers of clothing to hide his body type.