"Human Aid Company," an organization that helps improve human lives by ghost intervention, sends Masko to the human world to improve human circumstances. Masko is an erratic ghost and the worst employee in the company; he never fully succeeds in accomplishing his goal.
He is different from the other ghosts because he has a mask, that's why he is named masko. His speed is faster than other ghosts, because he is small and quick. His first move, short-range move, is using head to attack the opponent. His second move, long-range move, is spiting out little masko spirit to attack the opponent. His ultimate move, Masko will duplicate another Masko to help him during the battle.
The company knows that Masko would be failing his tasks again, so they send Jackrette, the best employee of the company, to look over Masko and try to help him in improving his skills. Jackrette's signature is his green jacket. Jackrette is the strongest ghost that has more experience than Masko, so his attacks can make more damage than Masko. But on the other hand, he moves very slow compared with Masko's speed.
Fevil is a ghost from the rival company of "Human Aid Company", which the company that he comes from does an opposite thing. Instead of helping humans, they make humans suffer. Fevil is a fire-type devil that has an arrow tail as his signature. Fevil is a cunning little devil, who has high speed and high attack points.