Ginta is a Japanese high school boy who often fantasizes about a land known as Mar Heaven. One day, he is mysteriously summoned to the imaginary land, which in fact turned out to be real. Upon reaching there, he learns of powerful weapons known as Arms that exist in Mar Heaven. With the companions and friends that he meets during his travels, the group seeks to destroy the Chess, a faction led by the mysterious
Phantom, which is determined to bring about Mar Heaven's Ultimate Demise for reasons unknown.
Dreaming of a magical world every night, the young Toramizu Ginta yearns to be able to go there. With only his friend
Koyuki believing in his dreams, Ginta remains positive despite the slander he receives from others over his dreams. But his wishes are answered, as one day a large door appears in front of Ginta, summoning him to the land of MAR Heaven. In this land, the weapons known as ARMS exist. While initially Ginta greatly enjoyed the discovery of this magical world, he soon learns of the terrible wars that have once plagued MAR Heaven and the upcoming war that may soon appear.
Ginta would much rather dream of fantasy worlds than do his homework; but when he dreams of the same place 102 times, he knows something is amiss. The 103rd time, his dream becomes a reality when he is whisked away to the enchanted lands of MAR Heaven, a place where magic and monsters really do exist, and the world is being torn apart by an evil queen. Now, before he can find his way home, Ginta must take on the queen with the help of newfound friends
Babbo,
Jack,
Alan and
Snow. Together, they could be MAR’s best chance of liberation from the hands of evil!