A user management server, a terminal, an information display system, a user management method, an information display method, a program, and an information storage medium are provided to enable a user to have less trouble than with existing techniques in registering users disclosing their real names. In response to a first operation to designate a user, a friend management data registration part registers the user as a user in a first relation involving disclosure of a nickname. In response to a second operation to designate a user already registered as a user in the first relation, the friend management data registration part registers the user as a user in a second relation involving disclosure of a real name as well. In response to a third operation to designate a user not registered as a user in the first relation, the friend management data registration part registers the user as a user in the first and the second relations.