You should speak with every student you can. This might be your only chance to see what they're really like before you become a professor...
Speak to the three house leaders and gather information about the students in each house. The students can be found in the reception hall on the first floor and throughout the Officers Academy.
  1. Accept the quest from Rhea.
  2. Speak to the three house leaders.
  3. Report to Rhea.
You are responsible for choosing which house to lead. If there are still students you have yet to speak with, try visiting each house's homeroom.