After being stood up for a movie date, marketing employee Fumihiko Matsumaru is about to throw away his tickets when he is stopped by a girl who implores him to let her accompany him instead. Thanks to his upbeat and eccentric companion Aka Onda, an aspiring voice actress, Fumihiko enjoys his evening. While walking home together, they find out that they live in the same neighborhood. Mere hours later, Fumihiko wakes up from a nightmare and hears sirens outside his window. Going outside to check the situation, he sees that Aka's apartment has burned down, along with all her possessions. Fumihiko invites the distressed Aka to stay at his place, leading to them sleeping together. In the aftermath of that fateful night, their personal and professional lives become inextricably intertwined. Not only do they begin living together platonically despite their one-night stand, they also discover that Aka will be voicing the mascot Fumihiko designed for his company's newest product. While trying to keep their live-in relationship under wraps for fear of scrutiny, the two begin to support each other throughout the difficulties in their respective careers.

On a train to her new middle school, Momoka Sonokawa is preyed upon by a molester, only to be rescued by a girl wielding dual pistols. The girl turns out to be Miou Ootori, Momoka's upperclassman and president of the Aogiri Academy's Survival Game Club, called Sabage-bu for short. Noticing Momoka's aptitude with a pistol, Miou takes a liking to her and tries to persuade her to join the club. In spite of her steadfast refusal, Momoka inexplicably finds herself a member of Sabage-bu. Sabage-bu is anything but a typical middle-school club. Its members' socially awkward behaviors scare Momoka. Their personalities range from the fanatical to the completely delusional. They do not hold back from walking around public areas wearing ghillie suits or even bungee jumping from the school building. Thrown together with this collection of survival game maniacs, the zealously ordinary Momoka must somehow adjust to her unexpectedly wild school life.

Aspiring light novel author Yuu Nagami regularly enters writing competitions but has yet to win a single one. Despite his recurring failures, he remains steadfast in his resolve to become a better writer. When he takes a look at the list of winning authors in the latest contest he joined, he notices that someone named Chikai Towano dominated the competition. He soon discovers that behind the pen name is his sister Suzuka—the last person he can imagine being an author. Suzuka cannot reveal to anyone that she is Chikai Towano and requests her brother to take her place. Yuu agrees with one condition: he will continue posing as Chikai Towano for his sister until he publishes his own book. Until that happens, Yuu uses his new identity as an opportunity to improve his writing skills and meet fellow authors and new acquaintances along the way.

Miach sends the Hestia Familia to find a rare herb on a deserted island. Unbeknownst to the group, a familiar face is also on the island and things will get chaotic. (Source: DanMachi Wiki)