The purpose of this paper is to seek a better understanding of why solely in Japan the concept of capsule living units has been perceived more than a mere utopia and seems to have "made sense" to a wide cultural audience as a possible housing alternative. For that purpose, a thorough literature review was conducted to bring about comprehensive understandings of this phenomenon through a historical review and a definition of the capsule as presented by the Metabolists in the 1960s, and through a comparison between its fundamentals and the one of its hypothetical ancestral precedent; the Japanese tea-hut.