This article argues about the phase transition of water and the destruction of boundaries in Kobo Abe’s texts written in the 1950s from the geopolitical point of view about the postwar period, especially about General Headquarters (GHQ), during the Allied occupation period in Japan. Abe has written about metamorphosis in many of his texts. Metamorphosis has been presented as the process transforming human bodies to things, or presented as the situation itself after the process is completed through the dissolving of boundaries and the reconstruction of the new body. The characters in Abe’s texts are weak and have low-social status, but they have the potential to transform themselves, which shows their dynamism. Heightening the phase transition of things and the violence of the underwater-world, Abe forces us to read the connotations of an unestablished cognition of boundaries shown in postwar society in Japan.