Kako gets jealous when Oobi gets a pet turtle and forgets about him and the playdate they had planned. Oobi realizes that Kako's feelings have been hurt and he apologizes. The boys have a great time together with the turtle. — ABC Television (source)
Kako walks into the living room and explains that he and Oobi are having a playdate. He knocks on Oobi's door using a "secret knock" that he and Oobi came up with. He invites the viewer to try out the secret knock as well. Oobi opens the door and shakes hands with Kako. The boys make three plans for the day: playing, drawing, and singing. They are interrupted by Grampu, who calls from the kitchen. The boys rush over and find out that Grampu has bought a pet turtle for Oobi. Oobi is amazed by the turtle and can't stop looking at it. Kako is visibly jealous and asks Oobi to play with him outside. Oobi comes and takes the turtle with him.
In the backyard, Kako suggests playing a game of tag. Oobi says no and asks to play "turtle peekaboo" instead. He takes a flowerpot and wears it on his head, pretending it's a turtle shell. Kako reluctantly joins him, but he ends up hating the game. He asks Oobi to draw with him instead. Oobi tries to bring his turtle along, but Kako tells him to leave the turtle.
They go inside and set up an art easel. Oobi is still focusing on his turtle and asks if the turtle is okay. Kako dismissively tells him that the turtle is fine. Kako draws a house with a blue marker, a sun with a red marker, and a tree with a green marker. Oobi takes a black marker and draws a turtle, making Kako mad. Oobi is completely oblivious and laughs at his turtle. He walks outside to see the turtle again. Kako follows him and asks to sing with Oobi. Oobi begins and sings "green, shell, oh, turtle!"
Kako immediately gets frustrated and explains that the turtle has become a problem. He storms off and tells Oobi to "enjoy" his turtle. Oobi realizes that he hurt Kako's feelings and apologizes. He gives Kako a handshake again. Kako decides that it would be best to play with both Oobi and the turtle, so he starts another game of "turtle peekaboo."
Later, Oobi appears in a few interview segments, asking preschoolers about their pets. Afterward, Grampu and the boys play a letter game where they find objects that begin with the letter "T." Oobi ends the game by saying "goodbye" to the viewers.