An avatar management system includes an avatar registration unit configured to register an available avatar by having a storage unit to store the avatar available in a network service provided to an end user on a network, an authentication information assignment unit configured to assign authentication information to a registration target avatar registered in the avatar registration unit, and an authenticity confirmation unit configured to confirm authenticity of a designated avatar based on an assignment condition of the authentication information to the designated avatar, in accordance with an authenticity confirmation inquiry made by designating the avatar used in the network service.