Marist Old Students Association (MOSA) is a non-political and non-governmental Organization of the former students of Marist Brother Secondary Dete, Zimbabwe (MBSS).
Vision: The vision of MOSA is to help the school/former school (MBSS) in its growth and development so that it may continue to produce proud, useful and distinguished service persons — persons who will not only be of good and useful service to the school but humanity as a whole, that is, Zimbabwe, Africa and the World.