Plot
Previosly in Luigi's Misadventures 3, Luigi saved Numbuh 9000 from Merla and traveled to South Nahow City to retrieve the five determination disks from Professor E.Gadd.
Numbuh 9000 explains that these disks are used to seal the most dangerous creations used by Galactic Kids Next Door. Luigi only has five chances to seal them.
Luigi, Rike and Numbuh 9000 departed to the outer space to search the whereabouts of the Galactic Kids Next Door. However, they ended in the Zero Space Station for refueling.
Luigi must stop the Galactic Kids Next Door in his own.