Touta Konoe is an ordinary boy raised in a small rural town. His mundane life suddenly changes when his mentor, Katherine McDowell, reveals herself to be a vampire; after saving Touta from a mortal wound, she causes him to become immortal as well. Already yearning to explore the world, young Touta finally puts his dream to ascend to the top of Amanomihashira—a tower that leads to outer space—into realization. Along the way, he finds a secret society filled with immortals just like him called "UQ Holders." Gaining new comrades and mentorship along the way, Touta embarks on his own unique, magical adventure. [Written by MAL Rewrite]

High school student Kaname Sudou receives an invitation from a classmate to play Darwin's Game, a mobile game he has never heard of. However, as soon as he opens the application, a green snake suddenly pops out from his phone screen and bites his neck, leaving him unconscious. Waking up in the infirmary without any signs of a snake bite, he is told by the school to take the rest of the day off. Although he is puzzled by what has happened, he dismisses the surreal experience as a hallucination and boards the train home. Unfortunately, his curiosity gets the better of him and he uses the application once again. As the application appears to be just like any other battle game, Kaname breathes out a sigh of relief and decides to start his first match. However, the pleasant surprise is short-lived, as his in-game opponent unexpectedly appears right in front of him and attempts to hunt him down with a knife. As he desperately runs for his life, Kaname puts two and two together and realizes that Darwin's Game is not an ordinary game, but rather, it's a brutal fight for survival. [Written by MAL Rewrite]

The story follows Iruma Suzuki, a 14-year-old human boy, who is sold to a demon by his parents. The demon, known as Sullivan, takes Iruma to the Demon World and officially adopts him as his grandson. He enrolls Iruma in the Babyls School for Demons where he is the headmaster and where Iruma quickly befriends the demons Alice Asmodeus and Clara Valac. However, Sullivan tells Iruma to never reveal that he is human since he will be eaten if anyone finds out. Iruma then vows to blend in during his time in the demon world, although he only stands out because of all the situations and adventures that arise.

In the eyes of the public, Fudou Aikawa and Desumi Magahara are sworn enemies who have nothing in common. Fudou, also known as "Red Gelato," is the leader of the hero squadron "Gelato 5," whose mission is to bring about world peace. On the other hand, Desumi is the minion leader of "Gecko," a villainous organization seeking world domination. However, despite these differences, their relationship is not quite what it seems. When they are not making a show of being at each other's throats, Desumi and Fudou continue to pursue a forbidden love. Going on dates, baking sweets for one another, and meeting up as often as they can despite their hectic schedules, the two inexperienced lovebirds pave the way for their own unique relationship. Though their public lives are worlds apart, Fudou and Desumi will stop at nothing to make their seemingly impossible romance work.