Because of the constantly declining birth rates over many decades, human civilization is all but extinct. With only a few humans remaining, they survive in this post-apocalyptic world with what was left behind by the previous generations. Earth is now dominated by fairies, tiny creatures with extremely advanced technology, an obsession with candy, and a complete disregard for human safety. A young girl who has just finished her studies returns to her hometown and is designated as an official United Nations arbitrator. Her duty is to serve as a link between mankind and fairies, reassuring each side that both races can live together peacefully. She imagines this task will be easy enough, but controlling the disasters created by the oblivious fairies in their pursuit of candy will require a lot more effort than she initially believes.

Takamine Kiyomaro, a depressed don't-care-about-the-world guy, was suddenly given a little demon named Gash Bell to take care of. Little does he know that Gash is embroiled into an intense fight to see who is the ruler of the demon world. All of the demons have to pick a master on Earth and duke it out with other demons until one survives. Needless to say, Kiyomaro becomes Gash's master, and through their many battles, Kiyomaro learns the importance of friendship and courage.

In the distant future, the nature of war has changed. Objects—massive, spherical tanks impermeable to standard weaponry and armed with destructive firepower—rule the battlefield; their very deployment ensures victory, rendering traditional armies useless. However, this new method of warfare is about to be turned on its head. Qwenthur Barbotage, a student studying Object Design, and Havia Winchell, a radar analyst of noble birth, serve in the Legitimate Kingdom's 37th Mobile Maintenance Battalion, tasked with supporting the Baby Magnum, one of the nation's Objects. Unfortunately, a battle gone awry places the duo in a precarious situation: mere infantry stand face-to-face against the unfathomable might of an enemy Object. As they scramble to save themselves and their fellow soldiers, a glimmer of hope shines through, and the world's perception of Objects is changed forever. Heavy Object follows these two soldiers alongside Milinda Brantini, the Baby Magnum's pilot, and their commanding officer Frolaytia Capistrano as the unit treks all over the globe to fight battle after battle. Facing one impossible situation after another, they must summon all their wit and courage to overcome the insurmountable foes that are Objects.

With a new year comes new adventures, especially at the Rabbit House! Since her arrival at the café, Kokoa Hoto has become accustomed to her new life as a waitress even though the Rabbit House isn't the rabbit paradise she initially envisioned it to be. Life is pleasant, and she enjoys spending time both working and playing with her friends and fellow waitresses Chino Kafuu, a cute middle school student with a fuzzy bunny companion named Tippy, and Rize Tedeza, the pig-tailed daughter of a soldier who is readily armed for any scenario. Together with Chiya Ujimatsu and Sharo Kirima, who also work at neighboring cafés in town, the Rabbit House crew gets involved in all sorts of crazy adventures. Throughout these adventures, the girls encounter troubled novelists, rival cafes, secret treasure, and... alcoholic chocolates?