The process of modernization and rise of modern cities have caused the dismantling of intermediate groups in our society. As a result, self-identity became reflexively formed, forcing individuals to make a variety of choices about their lives. It is becoming important to go beyond the traditional relationships, and to seek "reflexive cooperation" that can build relationships beyond these barriers. A prime example of reflexive cooperation is offline meeting where participants are recruited via an electronic bulletin board. This recruitment information details a desperate need for human being in the same situation as oneself. As such, the nature of the participants and the purpose of holding them can be seen as projecting a partition of majority and minority, from which we approach the nature of reflexive cooperation. Clarifying the conditions of such reflexive cooperation means to seek the environment for social inclusion, which can provide insights for urban planning.

 The purpose of this paper is to clarify the diversity of “reflexive cooperation” by social minorities, and its difference depending on population scale, by focusing on offline meetings as cases which the partitions of majority and minority were projected. There were two investigations and following was obtained:

 1) The types of reflexive cooperation by social minorities

 Firstly, by extracting and categorizing the narratives of the participants' characteristics from the information of offline meetings in the Tokyo metropolitan area, it was found that there were nine factors that defined the image of the participants: Age, Sex, Place of residence or territory of origin, History of immigration, State of mind, Characteristics of the body, State of kinship or state of love, Employment status, and Hobby or interest.

 Secondly, by extracting and categorizing the narratives about the purpose of the event, it was found that there were seven motivations for reflexive cooperation. By analyzing the relationship between participants and motivations, it was found that there were five directions of reflexive cooperation: Cooperation to build relationships on local or thematic, Cooperation in resolving alienation caused by the characteristics and changes in the work environment, Cooperation with the theme of migration experiences and hobbies, with the aim of escaping the usual interpersonal roles, Cooperation to escape from relationships that are rigid due to one's age, mental, physical, intimate, or work environment, and Cooperation that organizes itself as an escape from the local, family, or love that no other cooperation can satisfy.

 2) Difference of reflexive cooperation in number depending on population scale

 Thirdly, an analysis of relations between information about offline meetings and population in county seat locations revealed that the number of reflexive cooperation increases in proportion to population, and that the watershed on whether a variety of reflexive cooperation will try is between cities of 1 million and 400,000 people. It turns out that this depends on whether the participants attempt reflexive cooperation on: History of immigration, State of mind, Characteristics of the body, State of kinship or state of love, and Employment status.

 In conclusion, cities with less than 400,000 people must take measures to include social minorities who face the partition identified by this paper in a different way than the spontaneously organized offline meetings. Considering the limitations of both anonymity and planned inclusion, such as "a place for community," is an urgent task for today's urban planning.