Takemichi Hanagaki's life is at an all-time low. Just when he thought it couldn't get worse, he finds out that Hinata Tachibana, his ex-girlfriend, was murdered by the Tokyo Manji Gang: a group of vicious criminals that has been disturbing society's peace for quite some time. Wondering where it all went wrong, Takemichi suddenly finds himself travelling through time, ending up 12 years in the past—when he was still in a relationship with Hinata. Realizing he has a chance to save her, Takemichi resolves to infiltrate the Tokyo Manji Gang and climb the ranks in order to rewrite the future and save Hinata from her tragic fate. [Written by MAL Rewrite]

The legendary former hitman Tarou Sakamoto has thwarted numerous assassins after an enormous bounty on his head was issued. But he cannot seem to catch a break and simply take it easy with his beloved family. A mysterious and infamous figure known as Slur has brought a group of insane death row inmates to Japan, who hold back from nothing to eliminate their targets. Sakamoto is not the only target—the criminals have been assigned to kill various other people, including the new hires at Sakamoto's convenience store, Shin Asakura and Lu Shaotang. The situation escalates even further when the Order, a group of the most skilled Japanese assassins, becomes involved. As the inmates begin wreaking havoc, Sakamoto and his allies must remain vigilant for the sake of everything they hold dear.

In spite of his best time-leaping efforts, Takemichi Hanagaki continuously fails to prevent the present-day death of Hinata Tachibana, his adolescent love. The adult Takemichi grapples with grief and the ramifications of the Tokyo Manji gang's criminal empire—an unintended product of his timeline meddling. Though the gang once operated under the idealistic Manjirou "Mikey" Sano, it has now been taken over by the malicious Tetta Kisaki and, as a result, has abandoned its original optimistic intent. Despite feeling hopeless, Takemichi travels to the past once again to investigate Black Dragon, a rival motorcycle gang whose actions ultimately lead to Hinata's demise. There, he meets the young Hakkai Shiba, a fellow gang member whose older brother, Taiju, tyrannically rules Black Dragon. When Taiju brutally beats Takemichi in a one-sided street brawl, Hakkai attempts to withdraw from Tokyo Manji in apology—an act that Takemichi must prevent to spare Hakkai a grim future. Through a shared tragedy, Takemichi bonds with Chifuyu Matsuno, establishing a close comradery both boys desperately need. With Chifuyu on his side, Takemichi works to unravel the fates of Black Dragon's members, fighting to create a happy future for his loved ones.

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]