Diaper Duty 9: The Lost Island is a Diaper Duty Series game for the Wii3D. It features around the idea of a mystical artifact and it is one of the only games to have all of the star children, past and present in the same place at the same time.
After Dinosaur Land's temperature turned to normal Baby Yoshi found that some of the land in his Yoshi Island had chipped away and he found something he had never seen before, a large chest. Curiously he opened up the chest to find half of a map with a location marked in the middle of the Mushroom Sea, it was to lead to a great treasure known as the Star Heart.
However little known to the young Yoshi Prince K. Rool was in possession of the other half of the map and his intentions were less than desirable he was going to use the Star Heart to take over the world!
Yoshi knowing that it was the star children destiny to rescue the poor Star Heart he gathered together the other star children and they set off on an expedition across the Mushroom Sea to find the legendary artifact.
They traverse through multiple small islands often having to stop for various quests until finally reaching the Island where they believe the Star Heart is being held, as they approach the island they find they are too late and K. Rool has already stolen the star heart. Using their Star Powers they summon the past star children Baby Rosalina and Baby Bowser to give their power up as well and they transfer all of their power into the current star children and they defeat K. Rool and save the Star Heart, they fill the star heart up with their power and they are told that each one of them will have a fulfilling life ahead of them and they are each granted more power.
Diaper Duty 10: Koopa Kid's Revenge is the last game in the series.