Two years have passed since the final battle with Sephiroth. Though Midgar, city of mako, city of prosperity, has been reduced to ruins, its people slowly but steadily walk the road to reconstruction. However, a mysterious illness called Geostigma torments them. With no cure in sight, it brings death to the afflicted, one after another, robbing the people of their fledgling hope.
A small, lone Kappa miraculously survives over 200 years into modern day Japan, when he is found by young Koichi. Coo, who is secretly adopted by Koichi's family, searches with his new human friend for unpopulated places in hopes of finding any remaining of his kind.
Shoyo Hinata joins Karasuno High's volleyball club to be like his idol, a former Karasuno player known as the 'Little Giant'. But Hinata soon learns that he must team up with his middle school nemesis, Tobio Kageyama. Their clashing styles form a surprising weapon, but can their newfound teamwork defeat their rival Nekoma High in the highly anticipated 'Dumpster Battle', the long awaited ultimate showdown between two opposing underdog teams?
Naruto Uzumaki, Kakashi Hatake, Sakura Haruno, and Rock Lee are assigned to protect the prince of the Land of the Moon, Michiru, during his world trip; other escorts had been hired, but quit due to being treated poorly. The Land of the Moon is a very wealthy nation, so Michiru tends to buy whatever he wants, and has a very materialistic worldview. His Hikaru, also acts in much the same manner.
Shouyou Hinata, after losing to Kitagawa Daiichi Junior High's setter Tobio Kageyama in his first official volleyball match, transfers to Karasuno High, intent on finally having a proper volleyball team and getting his revenge on Kageyama. Upon arrival at Karasuno, however, Hinata finds out Kageyama has also gone to Karasuno. Initially at odds with each other, the two form an oddball combination and fight together with the other members of the volleyball club. Karasuno reunites with a former rival school, Nekoma High, in a practice match and reignites their school rivalry.
Inspired by a small-statured pro volleyball player, Shouyou Hinata creates a volleyball team in his last year of middle school. Unfortunately the team is matched up against the "King of the Court" Tobio Kageyama's team in their first tournament and inevitably lose. After the crushing defeat, Hinata vows to surpass Kageyama. After entering high school, Hinata joins the volleyball team only to find that Tobio has also joined.
The balance of the worlds is maintained by heroes. Suddenly, a red-hot meteor falls upon one of these worlds, called Neo World. An amnesiac youth named Wukong Impulse Gundam appears at the point where it landed. The chaos that starts with this incident spreads through the other worlds, one after another. At the same time, Zhuge Liang Freedom Gundam learns via astrology of an impending disaster. He and his sworn friend Liu Bei Unicorn Gundam take action to save the worlds from this crisis, and begin a journey along with Wukong.
What will Wukong Impulse Gundam think as he meets the heroes of each world? Will this youth bring about peace or catastrophe? Now begins a new story of heroes!