The story is set in Diamond Ore Country, of which Diancie is the princess.This is a country located deep underground, where the Pokémon Carbink live together in peace. The energy source of this country is a giant diamond called the Sacred Diamond, which can only be created by princess Diancie. However, the current princess doesn't yet possess the power to create such a diamond, and the current Sacred Diamond's power is soon going to run out, which would result in the end of the country. Diancie meets up with Ash and Pikachu, and set off together with them to search for the legendary Pokemon Xerneas, which possesses sacred power, but on the way, they find the cocoon where the Destruction Pokémon, Yveltal, who was said to have once destroyed life in Kalos, lies in wait.

(Source: serebii.net)

Mr. Money is holding another Tenka'ichi Budokai and Mr. Satan invites everyone in the world to join in. Little does he know that Bojack, an ancient villain who has escaped his prison, is competing. Since Goku is currently dead, it is up to Gohan, Vegeta, and Trunks to defeat Bojack and his henchman.

Gokuu Son and his friends are out camping when three mysterious enemies ambush them. After a quick fight, a fourth enemy named Cooler joins the fray. Seeking retribution for his younger brother Frieza after he was defeated, Cooler attacks Gokuu; however, the latter manages to escape with Gohan Son and goes into hiding. Unsatisfied and infuriated with the outcome, Cooler and his men begin the hunt to uncover Gokuu's location and kill him to carry out their plans of exacting revenge.

[Written by MAL Rewrite]

In his laboratory, biotechnology expert Dr. Kochin gathers the dragon balls intending to free his master Dr. Uirou, a mad scientist hellbent on ruling the world, forever frozen in the never-melting ice of the Tsurumai-Tsuburi Mountains. Attempting to locate the dragon balls, Gohan Son and Oolong arrive at the scene and are ambushed by several creatures known as "Bio-Men." Training nearby, Piccolo attempts to save them but is then attacked by three mysterious warriors. When the ice beneath them breaks, it cuts their altercation short, burying Gohan and Oolong within.

After regaining consciousness, they return home to Kame House only to encounter Bio-Men, demanding Muten-Roushi to follow them. Refusing, he easily defeats the creatures, piquing Dr. Kochin's interest. Under the impression of Muten-Roushi being the strongest man in the world, Dr. Kochin takes Bulma hostage, forcing Roushi's agreement to accompany him in mysterious plans involving his master. Who are Dr. Kochin and Dr. Uirou? What even is their purpose?

[Written by MAL Rewrite]