Henry Henderson

Henry Henderson is a history teacher and the housemaster of dormitory 3, Cecile Hall at Eden Academy. Henry is a mature and noble person, who places a high importance on "elegance". To him, elegance seems to be the way a person conducts themselves, and is not afraid to correct inelegant behavior in others.

This can be seen in his interview with the Forger family: he was calm and composed even after Loid smashed the table he was sat at.
When teaching, he observes and assesses the "elegance" of the students, although he understands that children occasionally need to frolic too.

(Source: Spy x Family Wiki)