Sakuya Otsuki is the son of a legendary detective, working to follow in his father's footsteps with his assistant, Lilithea. However, something's different about this high-school sleuth. Wherever he goes, he always manages to get himself entangled in his cases—as a murder victim! When Sakuya is tasked to infiltrate a luxury cruise ship, he finds himself killed once again. But every time he reopens his eyes, Lilithea is there by his side, ready to help him get to the bottom of the mystery...

Yukio was destroyed in battle and Tetsuo survived in an escape pod. After eight years in cold sleep, the escape pod finally lands back on Earth. But when Tetsuo emerges he finds a world in ruins, entirely frozen beneath a blanket of ice and snow—snowball Earth! What happened to humanity, how did the planet freeze over, and will Tetsuo be able to keep his last promise to Yukio?

Fuu and Rui, who used to be close, but have been a bit distant from each other recently. One day, Fuu encounters a mysterious spaceship and gains magical powers. At that same time, Rui also gains magical powers, and both transform into the adults they dream to be. The sisters' powers come with two conditions: their magic powers can only be used in one year, and no one must know about it. Unaware of each other's secrets, Fuu and Rui become active as idols.

By the mid-21st century, Tokyo's criminal underworld is ruled by Demon Lords—crime bosses who have undergone ether enhancement surgery, granting them terrifying superpowers. The only ones who can take them down are Heroes, bounty hunters who boost their own ether powers using the drug E3 (E-Three). With legalized killing as part of the job, being a Hero is less about justice and more about survival. Yashiro, known as the Reaper, is one such Hero—an independent enforcer who works alone. That is, until Jougamine, a high school girl and self-proclaimed "apprentice," forces her way into his life. Reluctantly taking her under his wing, Yashiro soon finds himself caught in a whirlwind of deadly conflicts.