We define "Ro-space" as a general term to represent subsidiary spaces such as "Ro", "Watadono", "En" and so on. Ro-space is regarded as the origin of "Roka". Japanese classical literature illustrates Ro-space as multi-functional space. Ro-space was a place for communication, life, play, path, gathering, observation, ceremony and so on. In particular, informal and private acts took place at En, which opened to a garden. Though En was more simple and more incidental than Ro and Watadono, it was significant space for the daily life. Roka after the Middle ages might inherite such characteristics of the Ro-space.