In a post-apocalyptic world, the treasure hunter Riot and his pretty sidekicks are searching for Eyes of Zalem, which they hope will guide them to Rido, the treasure of a long-lost Quall civilization. A limitless energy source, the Rido has the power to even restore life; but unfortunately for Riot, the evil Demsters are after it too.

After an awe-inspiring battle with Ichibei Hyousube—leader of the Soul Society's Royal Guard—the powerful Yhwach moves into the final stage of his master plan. He aims to slay the Soul King, the being whose very existence maintains the status quo of three worlds: Hueco Mundo, the Soul Society, and the realm of humans that Ichigo Kurosaki and his closest friends hail from. Conquering his own bout with the remainder of the Royal Guard, Uryuu Ishida joins Yhwach in his efforts to create a new world in his image. With a flood of resolution and newfound power, Ichigo rushes to stop Yhwach from accomplishing his ultimate goal and save the countless lives within the three existing realms. But Ichigo has a complicated lineage, one that leaves him susceptible to Yhwach's sinister influence. Meanwhile, in a final desperate gambit, Jirou Sakuranosuke Shunsui Kyouraku, the newly promoted head captain of the Soul Society's combat corps, enlists the help of an old enemy whose immense power may turn the tide of battle.

On the 20th floor of the Tower, the "Regulars" who have been permitted to enter have to undertake arduous and extremely expensive tests to rank up. Most abandon hope and choose to stay where they are—but not Ja Wangnan. Wangnan is determined to reach the top and become the king of the Tower. However, he is weak and has repeatedly failed the exam, with debt collectors tailing him. In desperation, he attempts the exam one more time, only to encounter a mysterious and powerful individual: Jyu Viole Grace, a member of the crime syndicate FUG. Cursing his rotten luck, Wangnan has no choice but to form alliances with strong people, including Viole—who still refuses to be part of any team. Amid a dire situation, Wangnan must find a way to change Viole's mind to finally advance past the 20th floor, or he will never get a chance to build his legacy.

The story begins when a middle school girl named Yume sees something fall from the sky, and meets a pale violet-colored kitten named Mew. It turns out that Mew has the power of "Yume Synchro" (Dream Synchro), the power to enter dreams. In the dream world, the girl and Mew collect Dream Stones.