Hikari Horaki

Hikari is the "class representative" (often shortened to "class rep"): in Japan this is a student leader elected by the class, whose duties include making sure that assigned daily routines (watering the plants/flowers, feeding the goldfish, etc.) are carried out, and generally seeing that good order and decorum are observed in class. Class reps also lead the class in the "Rise! Bow!" ceremonial greeting when the teacher enters the room (which Hikari is seen doing several times during the series). Essentially, "class representative" is more or less equivalent to "class president" in North American schools.
Because a major part of her job is to make sure the class follows proper protocol, Hikari first appears to be slightly aggressive and rigid. She might believe that herself, as she apparently thinks that her skill in cooking might be unexpected when she tells Toji about it (presuming that something so feminine would be at odds with her strong promotion of the rules).