The world of Duel Monsters is once again evolving with the development of a network called Link Vrains and a new summoning mechanic introduced as Link Summoning. By using this cyberspace, duelists can now create their own avatars and duel their way to glory within a virtual reality. However, much like the real world, the digital world is not free from war, conflict, and mysteries. Years ago, a hacker organization known as the Knights of Hanoi unleashed an attack on Link Vrains. Led by the anonymous Revolver, their aim was to annihilate the artificial intelligence program known as the Cyberse. After a failed attempt, one of their targets, Ignis, managed to escape and hide the Cyberse somewhere in the network. Five years later, high school student Yuusaku Fujiki encounters a strange artificial intelligence program while dueling in Link Vrains. Under the guise of his avatar named Playmaker, Yuusaku and his partner in crime, Shouichi Kusanagi, decide to join forces with the peculiar existence. As he seeks the truth behind a mysterious incident of the past, Yuusaku battles against the Knights of Hanoi and SOL Technologies in a race that might alter the fate of the world.

This anime is based on a playstation game under the same title. The story is about four people who travel the desolated land of Filgaea and carve themselves a legendary story while they're at it. These adventurers are Sheyenne Rainstorm, a gunslinger who holds the legendary weapon called ARMs; Kiel Aromax, a scientist who looks like he should be carrying a sword; Roleta Oratorio the Crest Sorceress, a magic-user who uses cards called Crests to cast spells; and Mirabelle Graceland, one of the Noble Red, which are a family of vampiric creatures who live alongside human beings They also travel with cute little intelligent furry things, from the Popepi Pipepo Tribe, named Isaac and Jerusha. (Source: AniDB)

As the head of her middle school's science club, it's only fitting that Ueno is also a brilliant inventor. With devices that can convert any liquid into drinkable water, deodorize the most foul smells, or even generate dark matter to be used as a means of concealment, it seems like nothing is beyond Ueno's capabilities. However, she doesn't invent these devices for the advancement of mankind. Rather, the one force that motivates her is love, the only phenomenon she can't quite figure out. Ueno is head over heels for Tanaka, her nonchalant fellow club member. Yet, because she is too nervous to confess her love and he is too oblivious to notice her affection, her love life is completely stagnant. In Ueno's mind, if she could just expose him to perverted situations, then surely he'd get flustered and fall for her, right? Assisted by her stone-faced classmate and dedicated wingwoman Yamashita, Ueno employs her many inventions on Tanaka in a lewd manner in hopes that he may one day understand how she feels. [Written by MAL Rewrite]

The Earth has developed a defense system against large meteorites that are on a collision course with it. This protection system is made up of the Comet Blasters based in several space stations as the 1st line of defense, using nuclear warheads launched by spaceships. The 2nd line of defense consists of the Meteor Sweepers launching from ground airbases using hypersonic planes with special missiles to deal with the resulting debris from the blasts. Mikaze is a troubled girl that is a trainee pilot for a Meteor Sweeper team that dreams of becoming a prestigious Comet Blaster pilot. Stratos 4 revolves around Mikaze's and her teammates' challenges to become real pilots, while the Earth faces the threats that come from space.