Each season, an idol group is given an infant or toddler to take care of, allowing them to experience parenthood to an extent. In the first season, Girls' Generation became 'mothers' to a nine-month-old boy. This was also the case for the boy band, Shinee, in the second season, though the child is four years old. In the third season, the girl group T-ara had to take care of three toddlers.
During the show's first three seasons, each group had to take care of the babies on their own, with some male celebrities acting as guest 'dads' in the first season. In the fourth season, Sistar became mothers to a baby boy, with Super Junior's Leeteuk as the father.
While all of the show's seasons have different concepts, they are still similar in ways such as the 'parents' being given missions and activities to do for the day with the children.
I. Season 1: Girls' Generation's Hello Baby
Hello Baby's first season premiered on June 23, 2009. With 9 members, Girls' Generation became mothers to a nine-month old boy named Cho Kyungsan. In the first episode, the members are given pointers about child care before they meet the baby. Each episode, guest fathers come on the show to help. At the end of the day, the dads pick 'best mom' who is given certain privileges and a 'worst mom' who is given some punishment, usually clean-up duties. They also occasionally play games and other activities. Girls' Generation's season was well-received, and its 5th episode ranked first among cable channels in its time slot. The show won 'Best Picture for Variety' at the 4th Korean Cable TV Awards in 2009. It ended with a total of 22 episodes on November 17, 2009.