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The two original class officers along with the the head of countermeasures.

Class 3-3 has two class officers/representatives: Tomohiko Kazami and Yukari Sakuragi. Yukari is succeeded by Izumi Akazawa after her death. Their jobs aren't really shown, but they presumably helped with Countermeasures (it is stated in the manga Tomohiko is also a Countermeasures officer, in addition to being class rep).

Being class officer was a more popular job than in Countermeasures, as Aya wanted to be one, though she was passed over in favor of Yukari, and later Izumi.