On Christmas Eve, four-year-old Miri Unasaka arrives in Tokyo completely alone, in search of her father. The bright lights and merry atmosphere guide Miri to a big hotel and a man with a delicious-looking cake. However, the child has just unknowingly walked into the center of an elaborate, foolproof plan for assassinating a dangerous mafia boss. Professional assassins Kazuki Kurusu and Rei Suwa live together, fleeing memories of their grim childhoods and avoiding emotional connections. When their mission goes awry and they end up bringing Miri home, there is only one reasonable thing to do: return Miri to her mother. But the girl's innocent laugh and pure worldview quickly enamor her to Kazuki, who secretly enjoys playing a parent, and it is not long before Rei's impenetrable heart makes room for Miri. Miri's every move is unpredictable, and Kazuki and Rei find raising an energetic child harder than any of their missions. Although it presents a great risk to their careers, Kazuki and Rei—both assuming the affectionate nickname "papa"—decide to provide Miri with a normal childhood despite all the odds stacked against them.

In the near future, augmented reality has become a key part of daily life. A gentle middle school girl named Yuuko "Yasako" Okonogi and her family have just moved to Daikoku City despite rumors of people disappearing. There, her grandmother, nicknamed "Mega-baa," runs a shop called Megasia that specializes in illegal tools which interact with parts of the virtual world. Mega-baa also hosts an unofficial detective agency called "Coil," a group of children around Yasako's age who find and handle corruption of the virtual world. Yasako gets involved with the group when Fumie Hashimoto, a playful member of Coil, helps rescue her cyberdog Densuke after getting trapped in virtual space while chasing a mysterious virus. Also investigating these corruptions and viruses is an abrasive hacker named Yuuko Amasawa, who the others take to calling Isako. Can Coil discover the truths behind the mysterious viruses and corruption, and if they can, at what cost? [Written by MAL Rewrite]

The dawn of a decisive battle nears in Leyte Gulf against the Abyssal Fleet, the mysterious enemies that occupy the sea. As the only ones capable of fighting them, Kanmusu—young girls possessing the souls of warships—reorganize in preparation. The Shiratsuyu-class destroyer Shigure is assigned to the First Striking Force, Third Section—also known as 1YB3H. Unfortunately for Shigure, 1YB3H consists of the remaining few Kanmusu and serves as a diversionary fleet. Needing to confront the Abyssal Fleet head-on, it may well be their first and final mission together. Even so, Shigure refuses to let the enemy take another comrade from her. As they advance toward Leyte Gulf during this suicidal mission, the members of 1YB3H must support each other and persevere to prove their worth as competent ships.

Jashin-chan is a demon who was summoned by Yurine Hanazono, a gothic looking girl. Unable to return home as the relevant spell was not included in the summoning grimoire, Jashin-chan resorts to violence to liberate herself from her earthly shackles. However, this is easier said than done, as Yurine is no weakling herself. She in fact possesses formidable physical power and uses it to massacre Jashin-chan in a variety of ways, be it shoving her arm in a blender, spreading her intestines across the room or even cooking her. Though these actions would be fatal to anyone without the ability to regenerate, Jashin-chan isn't exactly undeserving of this treatment. Stuck with each other, Yurine lets Jashin-chan live with her in exchange for work around the apartment, and this cohabitation results in situations where, more often than not, Jashin-chan ends up in pieces. [Written by MAL Rewrite]