On her 16th birthday, Himari Momochi receives a letter stating she has inherited a mansion called the "Momochi House." Having been raised in an orphanage, this mansion is the only thing left of her real family, so Himari pays no mind to the rumors that it may be haunted. Upon entering it, she meets Aoi Nanamori and his companions, Ise and Yukari, who all seem to be squatting in her new home. Although they warn her to leave the house, Himari vows to be the one to make them leave instead. But soon, she is attacked by youkai and finds out that the house sits in the space between the world of the living and the spirit realm. Even more surprising, Aoi was chosen to be the guardian of the house—a position originally meant for Himari. But this great power came with an awful price: Aoi can never leave the mansion, and his existence in the human world has been erased. Ignoring his pleas for her to leave the mansion, Himari promises to help Aoi break the housebound curse as she begins living under the same roof as him.

During their decade-long quest to defeat the Demon King, the members of the hero's party—Himmel himself, the priest Heiter, the dwarf warrior Eisen, and the elven mage Frieren—forge bonds through adventures and battles, creating unforgettable precious memories for most of them. However, the time that Frieren spends with her comrades is equivalent to merely a fraction of her life, which has lasted over a thousand years. When the party disbands after their victory, Frieren casually returns to her "usual" routine of collecting spells across the continent. Due to her different sense of time, she seemingly holds no strong feelings toward the experiences she went through. As the years pass, Frieren gradually realizes how her days in the hero's party truly impacted her. Witnessing the deaths of two of her former companions, Frieren begins to regret having taken their presence for granted; she vows to better understand humans and create real personal connections. Although the story of that once memorable journey has long ended, a new tale is about to begin.

Rentt Faina, a 25-year-old adventurer, has been hacking away at monsters for a decade. Without much talent for the job, Rentt finds himself stuck hunting slimes and goblins for meager amounts of coin every day. Little does he know, all this is about to change when he comes across a seemingly undiscovered path in the Water Moon Dungeon. What awaits him at the end of the path, however, is neither treasure nor riches, but a legendary dragon that wastes no time swallowing him whole! Waking up a short time later, Rentt finds himself not quite dead, but not very alive either―He is nothing more than a pile of bones! Armed with nothing but his trusty sword, tool belt, and ghoulish new looks, Rentt sets off on his quest as a newly reborn skeleton to achieve Existential Evolution, hoping to one day return to civilization with a more human form. Will Rentt succeed, or will the dungeon consume him for the rest of his un-death...?

Even though Sasaki's droll corporate life is constantly filled with work, it leaves him tired and unfulfilled at the end of every day. In search of some companionship to fill the emptiness in his life, he visits a pet shop on a whim, not realizing he's about to change his life forever. After settling on an adorable bird and bringing it home...his new roommate reveals that it's actually an incredible sage from another world who promptly bestows Sasaki with supernatural powers as well as the ability to cross between worlds. All Sasaki wants to do is use these newfound powers to live in peace and comfort, but there are more than a few colorful characters who might get in the way of that...