In the bustling and futuristic city of Heartland, a young boy named Yuuma Tsukumo has a dream that everyone his age wants to achieve—earning the title of the greatest duelist! Sadly, due to his lackluster dueling skills, this dream is far from achievable. But when the school bully, Ryouga Shark Kamishiro, splits the key given to him by his father into two pieces, he inadvertently sets Yuuma on a collision course with his dream. Retaining one half of the key, Yuuma begins a duel with Shark, but soon realizes that his inexperienced skills are no match for him. In a sudden turn of events, Yuuma's key repairs itself, and the Door of Destiny'' appears before him. Using the key to open it, Yuuma is greeted by an alien by the name of Astral—a being only he can see. The bewildered Yuuma soon learns that his memories have been divided into 100 Number Cards, all of which he must retrieve. However, he is also not the only one looking for them. Bombarded by these revelations, Yuuma, alongside Astral, must defend the world from the upcoming threats that loom over Heartland City—regardless of any divine intervention that may occur.

Tsubasa Kazanari and Kanade Amou—the idol duo known as Zwei Wing—use their songs to power ancient weapons known as symphogears to combat a deadly alien race called the Noise. While the general public is aware of the Noise's existence, knowledge of the symphogears are kept a secret. When the Noise attack one of Zwei Wing's concerts, Kanade sacrifices herself to protect a young girl named Hibiki Tachibana, leaving Tsubasa devastated and a fragment of her symphogear embedded within Hibiki. Two years pass and Hibiki is once again dragged into a Noise attack. While rescuing a young girl who has been left behind during the evacuation, she awakens the power of Kanade's symphogear lying within her. Although Tsubasa still grieves over the loss of Kanade, both girls must now learn to work together using their powers to defend humanity against the Noise.

In the year 19XX, after being betrayed and left for dead, bravehearted warrior Kenshirou wanders a post-apocalyptic wasteland on a quest to track down his rival, Shin, who has kidnapped his beloved fiancée Yuria. During his journey, Kenshirou makes use of his deadly fighting form, Hokuto Shinken, to defend the helpless from bloodthirsty ravagers. It isn't long before his exploits begin to attract the attention of greater enemies, like warlords and rival martial artists, and Kenshirou finds himself involved with more than he originally bargained for. Faced with ever-increasing odds, the successor of Hokuto Shinken is forced to put his skills to the test in an effort to take back what he cares for most. And as these new challenges present themselves and the battle against injustice intensifies, namely his conflict with Shin and the rest of the Nanto Seiken school of martial arts, Kenshirou is gradually transformed into the savior of an irradiated and violent world.

The sequel to Saint Seiya: The Lost Canvas - Meiou Shinwa.