The Palaceside Building's birth was decided exactly 60 years ago, on June 21. On that day in 1963, leaders of Reader's Digest, The Mainichi Newspapers and Sanwa Bank — the future clients — gathered at the Meguro Guest House and signed a preparatory agreement promising that the three companies would build a building together.
The agreement states that they would cooperate in thorough study of a plan to establish a jointly funded company (provisionally Takehira-cho Building Co.) whose main purpose would be to lease land at 1 Takehira-cho, Chiyoda, Tokyo, construct a modern high-rise on it and operate it as rental property. Takehira-cho is the former name of today's Hitotsubashi. Three years and three months later, the Palaceside Building opened.
(The photo shows officials signing the preparatory agreement. From "Palaceside Building 50-Year History.")