In the heart of the 1970s, a young Gru is growing up in the suburbs, a fanboy of a supervillain supergroup known as the Vicious 6. He hatches a plan to become evil enough to join them with the help of his loyal followers, the Minions. The Minions, with their own brand of chaotic energy and emerging language, endeavor to learn the ways of villainy to aid their young master's ambitions. Gru lands an interview to join the Vicious 6, but things go awry, leading him and the Minions to undertake their own adventure. As Gru tries to prove his villainous mettle, the Minions' efforts to support him often result in comical misadventures.

The Minions' quest leads them to acquire guidance from an unlikely source, the skillful yet somewhat washed-up former member of the Vicious 6, who helps them hone their skills. Meanwhile, the current members of the Vicious 6 are in possession of a powerful object that Gru covets, which they plan to use for their nefarious plans. As Gru starts to put his cunning plan into action, getting closer to the Vicious 6, his innocence begins to blend with a growing sense of cunning. This sets the stage for a collision of ambitions, heists, and loyalties as Gru and the Minions carve their path in the villainous world, setting the groundwork for the future of their despicable adventures.