First Day is the 22nd episode of season two. In this episode, Mordecai and Rigby get their job, and fight over an old chair.

This is an updated version of the pilot episode. Mordecai and Rigby find a newspaper ad posted by Benson to get two groundskeepers. Mordecai and Rigby answer the advertisement to Pops, who gives them the job. They get their bedroom (which is empty at the time), and drink two cases of soda. They bring in a pile of old clothes, a blanket, a pillow, and an alarm clock. When they wake up the next morning, they act like how Doug acted when he got a job as a temp. On Punchies, Mordecai wins the bowl of cereal and the spoon. Benson and Pops come in, carrying an old sofa, and Mordecai and Rigby follow them outside to claim the chair. Pops and Benson say that they are throwing it out, and Benson drives away, leaving Mordecai and Rigby skeptical about the explanation. However, both find it uncomfortable, which explains why Benson explained that they were throwing it out. Mordecai and Rigby play Rock, Paper, Scissors for the couch. After tying for the 100th time, a black hole enters, while the crowd runs away for cover, but one was sucked up. Rigby goes for the chair, Mordecai goes for Rigby, and Pops goes to save both. Pops warns Benson and Skips, and both split up. Skips gets to the three first, and Benson comes a few seconds later. However, the gang sees that Rigby was halfway sucked into the black hole, so Benson drives to the garage, getting Rigby out, but only half the chair. Skips yells to Mordecai and Rigby that the only way to get rid of the black hole was to beat the contest. Mordecai promises he was gunna pull rock next, though Rigby was at first skeptical about it. But it happened, and the black hole was gone. Rigby saw only half the chair, so he said “Cool” and called it. Benson then said that Mordecai and Rigby had to flip over the overturned golf cart, throw away the half chair, and clean up that mess “OR YOU’RE FIRED!!!!!!!!!!”, turning red at the previous quote, Then Mordecai & Rigby promises not to screw up the next day, after that Rigby plays Rock, Paper, Scissors again with Mordecai to pick up the cart, Then the screen goes blank.