Cinque returns to the land of Flonyard in Dog Days' to resume his duties as the hero of the Biscotti Republic and it's as though he never left! The difference this time is that he's brought two friends with him who become heroes in their own right: childhood best friend Rebecca Anderson, who becomes the hero for the Principality of Pastillage at the urging of their leader Princess Couvert Eschenbach Pastillage, and his cousin Nanami Takatsuki, who becomes the hero for the Galette Lion Dominion. As with the first season though, with so many secrets to be uncovered and mysteries to be solved, will there even be time for the athletic events that these three hyper and athletic teenagers love to participate in so much?

After five years of harboring unspoken feelings, high-schooler Taiju Ooki is finally ready to confess his love to Yuzuriha Ogawa. Just when Taiju begins his confession however, a blinding green light strikes the Earth and petrifies mankind around the world—turning every single human into stone. Several millennia later, Taiju awakens to find the modern world completely nonexistent, as nature has flourished in the years humanity stood still. Among a stone world of statues, Taiju encounters one other living human: his science-loving friend Senkuu, who has been active for a few months. Taiju learns that Senkuu has developed a grand scheme—to launch the complete revival of civilization with science. Taiju's brawn and Senkuu's brains combine to forge a formidable partnership, and they soon uncover a method to revive those petrified. However, Senkuu's master plan is threatened when his ideologies are challenged by those who awaken. All the while, the reason for mankind's petrification remains unknown. [Written by MAL Rewrite]

Emperor Pilaf finally has his hands on the Black Star Dragon Balls after years of searching, which are said to be twice as powerful as Earth's normal ones. Pilaf is about to make his wish for world domination when he is interrupted by Gokuu Son. As a result, Pilaf flubs his wish and accidentally turns Gokuu back into a child. After the wish is granted, the Black Star Dragon Balls scatter across the galaxy. However, Gokuu discovers that they will cause the Earth to explode unless they are all brought back within a year. Uniting with his granddaughter Pan and a young adult Trunks, Gokuu sets off on an adventure through the universe to find the Black Star Dragon Balls and save his planet from destruction. [Written by MAL Rewrite]

After the defeat of the demon lord Hadlar all of the monsters were unleashed from his evil will and moved to the island of Delmurin to live in peace. Dai is the only human living on the island. Having been raised by the kindly monster Brass, Dai's dream is to grow up to be a hero. He gets to become one when Hadlar is resurrected and the previous hero, Avan, comes to train Dai to help in the battle. But Hadlar, announcing that he now works for an even more powerful demon lord, comes to kill Avan. To save his students Avan uses a Self-Sacrifice spell to attack, but is unable to defeat Hadlar. When it seems that Dai and Avan's other student Pop are doomed a mark appears on Dai's forehead and he suddenly gains super powers and is able to fend off Hadlar. The two students then go off on a journey to avenge Avan and bring peace back to the world. (Source: ANN)