Yasuko was born the fourth child - the fourth girl for the Okubo family. The family was to later welcome the fifth child who turned out to be a boy. Therefore, Yasuko had 3 older sisters, Makiko, Seiko, and Mieko, and 1 younger brother, Kazumasa. However, it was said that there was another son, much older than Yasuko, who had passed away at some point. It would be greatly appreciated if anyone could offer any information about this older brother, such as his name, when and how he died, how close he was with Yasuko, etc.