When Miss Simian sees Gumball and Darwin joyful on Monday, she knows that something is wrong with them. She performs tests on them, but the nurse disapproves what she's doing. But suddenly, Gumball and Darwin start to infect the school with the 'Joy Virus', and it's up to Miss Simian and her tape player to cure the students.

When Gumball and Darwin begin to complain about every little thing in their lives, the people of Elmore City mistakenly assumes charity cases and put together a benefit to raise money for them, leaving them having to fix the mix-up.