Boke

In Japanese comedy, a boke (boke literally meaning fool) is a character who says or does something silly or nonsensical, only to be cut off by the tsukkomi. Much of the humour of Seitokai Yakuindomo comes from the interactions between the bokes and tsukkomis.

It should be noted that someone who is boke in one situation can be the tsukkomi of another (for example, Shino Amakusa is usually a boke, but becomes a tsukkomi when dealing with Naruko Yokoshima). However, some characters are boke through and through, like Kotomi Tsuda or the aforementioned Naruko.