Nintendo’s president Satoru Iwata interviewed Miyamoto asking questions regarding the development of the recently released Super Mario Galaxy 2 where Miyamoto revealed what he learned talking to the producer of the game, Koizuma.
While talking about working with Koizumi-san, producer of Super Mario Galaxy 2, Miyamoto said,
So during the development of Super Mario Galaxy 2, Miyamoto tried to get these story elements cut back, but they kept creeping back in. He also showed the game to Tezuka-san and Nakago-san(worked on both Mario and Zelda games in the past) partway through development and they both said something was wrong.
Finally Miyamoto had a discussion with Koizuma and while recalling the conversation Miyamoto said,