Oobi is reading a board book in the living room while Uma plays with some blocks. Uma tells Oobi that she's building a house for her doll. Grampu greets the kids and helps Uma build her block house. Uma notices that he's wearing a purple bow tie, and Grampu explains that it's for his night out with Inka. He's planning to dance the polka. Grampu does a little dance, and Uma asks if she can come to dance with him and Inka. He says that only grown-ups will be at the dance, and that he's hired a babysitter to take care of the kids. Uma is upset.
Grampu hears the doorbell ring and answers it. A teenager named Randy walks inside and greets the family. He gives Oobi a "high-five" and tries to do one with Uma, too, but she refuses. Inka calls Grampu from outside, asking him to join her. He rushes to her after saying "goodbye" to the kids. Oobi invites Randy to read his board book from earlier. Randy gives Oobi the nickname "Oobi-Dude" and tries to make Uma feel better. He offers to help Uma with her block house, but Uma says no. Randy gives Uma some space and starts a guessing game with Oobi. He acts like different animals, then acts like Grampu.
Uma can't help but laugh at Randy's impression. Randy pretends to have a conversation with Uma's doll and dances the polka with it, eventually winning Uma over. She gives him the nickname "Randy-Candy" and plays another guessing game with Oobi. Randy tells the kids that it's time for bed. While Oobi and Uma get ready, an interview segment plays. It involves Kako asking kids about their babysitters. The next scene shows Randy singing the "Rockabye Lullaby" song to Oobi and Uma. Grampu returns as he sings. Oobi says "goodbye" to Randy and to the viewers as the episode ends.