When asked about being a father soon, Kokubun admitted that it was quite conflicting for him. Even though he has always wanted children, the feeling of impending father hasn't sunk in yet. In response, one of the guests Hiromi said that it takes time for men to accept the fact that the baby is on the way but it will happen naturally overtime. Kokubun's junior NEWS' Kato Shigeaki suggested that if it's a baby boy, he can join Johnny's in future while other guests suggested that if it's a girl, she can join Takarazuka when she grows up. This led Kokubun to express surprise at the suggestion and he said that he should probably start thinking about it now.
After the end of the programme, Kokubun also sent a fax statement to the media where he revealed that his wife is already 6 months' pregnant and is due to give birth in the end of October. He was surprised at first when told of the news but is now eagerly awaiting the arrival of the child. He pledged to work harder in his career and asked for the warm support of everyone around him.
Kokubun got married to a former employee of TBS in September last year and this will be their first child.