In the Fifth Year of the Keicho era, the Tokugawa clan sought to solidify their control of Japan. Hidetada Tokugawa has come to the doorsteps of Ueda Castle with the intentions of having the Sanada clan open its doors to him. But the Sanada and their retainers have other plans...

1532. Esteban, age 12 is a foundling from Barcelona, with a mysterious power of ordering the Sun to appear, for which he is called "Child of the Sun." Upon the death of his adoptive father, Esteban learns he was rescued as a baby from a sinking ship in the ocean. The mysterious medallion that Esteban wears since ever has a trace somewhere in the New World, probably coming from the Mysterious Cities of Gold. Esteban leaves Spain to find his parents and find out who he is. On the way he meets Zia, an Inca girl who was kidnapped from her people years back and has exactly the same medallion as him. Later on, they are joined by Tao, a young Galapagos robinson, the last descendant of the Empire of Heva, an Empire said to have built the Cities of Gold. Following Coyolite, the shining star represented on their medallions, the three children travel through the unexplored New World, searching for the Cities of Gold, believing that this way is leading them to their lost parents.

"This party doesn't need an incompetent magician who can only use supportive magic. You're fired, Alec Ygret." Suddenly, Alec, a court magician who had joined the crown prince's party to help him conquer dungeons—was banished from the party. And not just the party, but the crown prince's harassment has banished him from the royal palace as well, and a friend from the "magic academy" approached Alec, who was at his wit's end. "Hey, Alec. Do you want to try to conquer the dungeon with us again?" And so, together with the friends he used to party with, Alec begins his second journey in life. This is the adventure story of a former court magician who had been abandoned. Four years ago, the "Lasting Period," a party of four that had been called "legendary," has gradually spread its name around the world.

Under the capital city of Tokyo, Japan, there exists a large, vast, and unknown world known as Underground. There, people known as Elemental Users exist; people who have the ability to control the elements: Fire, Water, Lightning, Magnetism, Freeze, etc. Meet Rumina Asagi and his best friend Ginnosuke Isuzu, two average high school freshmen who reside in Tokyo. When they meet Gravity User, Chelsea Rorec, and the Miko of Life, Ruri Sarasa, their whole lives change into one big adventure.