Banpaku-keikaku is the master plan of Expo'70 designed by Tomoya Masuda & associates. Banpaku-keikaku has following characteristics: 1) Exhibition areas and artificial lake are designed to make a total view of the site. 2)Manipulation of the topography is related to placement of exhibition areas. 3)Viewing of the Expo starts with getting a total view of the site by the transportation. 4)With these elements, Banpaku-keiakaku was designed to achieve an idea called Keikan-ka, which is making a new landscape that has a new meaning. 5)Banpaku-keikaku were designed based on usage of former site. This work is important because concepts of discernment and manipulation of the topography and Keikan-ka which are related to Masuda's thoughts are utilized. Therefore, the author has studied its ideas and characteristics on the preceding paper (2019). Based on that paper, the author aimed to reveal how they developed that ideas and characteristics on this paper. There are two important materials for this aim which are made before completion of Banpaku-keikaku. That are four drafts for Banpaku-keikaku, and examination of the two past exposition, which are Lausanne Expo'64 and Montreal Expo'67 by Tomoya Masuda & associates. The former are included in a unpublished blueprint book 『JEXPO’70 会場計画』,which is discovered by the author, the latter are included in 「万博計画［Ⅰ］」,which is a published articles of Banpaku-keikaku. The author studied these materials.
In chapter 2, the author re-draw and analyzed four drafts, which are drawn by Kunio KATO, Shigeyuki OKAZAKI, Go SHIRAI, and Takashi TANAKA. And we found following 2 points. 1)Banpaku-keikaku may be based on KATO's draft. This is because KATO’s draft has many points of similarity to Banpaku-keikaku, in particular only KATO’s draft shows usage of former site.2) Making a total view of the site are not aimed on any drafts so that Keikan-Ka do not exists at the preliminary design of Banpaku-keikaku.3) Concepts such as discernment and manipulation of the topography, and regarding usage of former site as important are not aimed on all drafts. Accordingly, these ideas do not exist at the preliminary design of Banpaku-keikaku.
In chapter 3, the author analyzed Masuda & Associate's examination of two past exposition and found following 3 points. 1)They found the defect of Lausanne Expo that is there are no areas to synthesize the expo. Masuda's plan was designed after solving that defect. 2)They found that Montreal Expo is designed after utilizing the existing topography such as Saint-Lawrence River and the island and pier of the site. Masuda's plan was designed after developing that way to achieve Keikan-ka with artificial lake and placement of the exhibition areas. 3)They examined Montreal Expo from the perspective of reading the topography.
Conclusions are as follows. 1)Discernment and manipulation of the topography does not exist in the four drafts. But Masuda & associates examined the Montreal exposition from the perspective of reading the topography. 2)The four drafts were not designed to realize an idea called Keikan-ka. And the two past expositions did not examined from the perspective of whether the expositions were designed to make the site seen as one united area like Banpaku-keikaku was. 3)Characteristics of Banpaku-Keikaku took shape after drawing the four drafts.
