One day, Baby Bowser and Kamek were taking a walk. Baby Bowser spotted some strawberries. He started eating them. Kamek then got mad at him for eating them, and Baby Bowser got mad. He squished Kamek and saw Kamella. He hired her (although she was unwilling.)
Meanwhile, Kamek was flying around. He saw the Star and Moon children and remembered they had defeated him before. He kidnapped them. A bunch of babies and Yoshis witnessed this and went to stop him, forming the "Sun Children".
main article: Sun Children
All Yoshis from YI.