According to an embodiment, a communication support apparatus supports communication among users. The apparatus includes a message receiver to receive a message from a user terminal; a participation request transmission controller to control such that, when the received message is a participation request message, the participation request message is transmitted to a user terminal to which the participation request message is to be transmitted; a response receiver to receive a response to the participation request message from the user terminal to which the participation request message has been transmitted; a group generator to generate a conversation group including as members the user terminal that has responded to the participation request message and the user terminal serving as a transmission source; and a conversation controller to control delivery of messages in the conversation mode such that a message received from a member of the conversation group is transmitted to another member.