It has been many years since the ghost wars and no one except for Pacster believes in Ghosts anymore. But when Pacster opens a portal from the Netherworld, ghosts come into Pac-World. Pacster meets President Spheros who tells him each berry gives him a different power, but they all allow him to defeat ghosts. It also keeps the planet alive so they must protect it. The Ghosts try to take the Tree of Life, but Pacster eats most of them and the last ones (consisting of Blinky, Inky, Pinky, and Clyde) surrender. They think they won until they find out the Ghosts have the Tree of Life

Pacster, his friends, and the Ghosts who surrendered sneak into the Netherworld to take back the Tree of Life. It turns out to be a trap, but Pinky thinks Pacster has a crush on her. At first he denies but his friends tell him to say yes and when he does, him and his friends are let out.

When Betrayus can't defeat Pacster (now known as Pac-Man), he clones a bunch of monsters to create an army that Pac-Man can't eat. Inky, Blinky, Pinky, and Clyde warn him and he uses the berries against the monsters. But one monster saves him when he runs out of berries and they want to keep as a pet but only one problem: no pets allowed in the dorm.

Dr. Buttocks creates a machine that makes giant monsters, but Pac-Man uses a berry to make him giant too. He defeats one monster, but there is still one left and the berry wears off. Just then Sir Cumference comes with a shrink ray and Pac-Man goes into the monster's mouth to shrink it. Meanwhile, the pet is too much so they give it to Sir Cumference.

Betrayus finds out Pac-Man's weakness is food. So Betrayus forces Inky, Blinky, Pinky, and Clyde to make Pac-Man too full to eat ghosts. When the ghosts steal too much food, President Spheros limits him to three meals a day, but Betrayus makes him eat Netherworld food. He gets full and ghosts attack, but Clyde burps him and he eats the Ghosts. Back in the Netherworld, there is no more food.

When Ghosts attack President Spheros, Dr. Buttocks possesses him as part of Betrayus' plot to find the repository that is holding Betrayus' body. Pac-Man and his friends go to see Sir Cumference and get a Paco-Strobo-Cacophonater. The possessed President Spheros makes everyone hate Pac-Man and Pac-Man finds out he's been possessed. He makes Pac-Man give him the berries, but it is actually the Paco-Strobo-Cacophonater which gets Dr. Buttocks out of President Spheros' body.