In studying solidarity theoretically interesting question is extended solidarity among different communities, because this extension process should include some kind of emergent properties. In this paper we seek out empirical approaches to exploring this theoretical issue. For data, we mainly use 2012 Solidarity Survey in Kyushu area and additionally use 2007 Solidarity Survey in Fukuoka for comparison, both of which the author conducted under the similar framework. At first, in terms of factor analysis we extract two basic axes of solidarity, homophilic and heterophilic, and fix four types of sense of solidarity based on the combination patterns between the two. Considering the above-mentioned extension process, the most attracting type is the coexistence type that indicates high scores both for hemophilic solidarity and heterophlic solidarity. We will find two important factors, family unity and diversity of net-base, that determine this type of coexistence, suggesting that issues of coordination of bonding and bridging social capital are related to the abovementioned emergent properties. Since coexistence type is also determined by gender and social class the extension of solidarity can be related with these barriers of difference. Secondly, we explore the extension process of solidarity from the viewpoint of impact of external factors, in this case, the Kyushu Shinkansen and the Great East Japan Earthquake. Unforeseen overlapping of these two events and resonation of their impacts through the discourse space seemed to strengthen Japanese people's sense of solidarity at the national level beyond the boundaries of concrete regional solidarity. In fact, we will find some empirical evidence that solidarity as Japanese people was strengthened between 2007 and 2012 . We will also find that the Kyushu Shinkansen did not cause breakdown of solidarity as Kyushu, however it is difficult to identify its unique effect of strengthening it.