Hämsterviel re-corrupts some experiments using a recording of Angel's siren song and causes them to do chaos again, disrupting a class project at Yuna's school to build a playground for an upcoming festival. Link binds Yuna and Penny together, and Babyfier transforms everybody else (apart from Stitch) into tiny babies. While Stitch takes care of the babies, Yuna and Penny must try and co-operate together to find the antidote to get everyone back to normal.

It's Christmas time, and when Gantu accidentally sends Experiment 267 (Wishy-Washy) instead of Experiment 297 (Shortstuff), Stitch decides to use Wishy-Washy's ability to grant people's wishes to raise up his good deed counter. However, Yuna wants to get something for Gramma, but she tells her she doesn't need to get her anything. When Penny kicks Ted out of her entourage, he wishes he could ruin Penny's Christmas party and Wishy-Washy accidentally turns her Christmas tree into a monster, and with no more wishes left, Stitch and the others must save Penny.