One day, the supervisor in charge of watching over Earth was taking care of a distortion, when they made a mistake that caused Kaoru Nagase to lose her physical body. Not only that, but reincarnating her into a different, less culturally-advanced world is the only thing they can offer to do for her.Not one to take this turn of events sitting down, Kaoru makes a demand: the power to create potions at any time she pleases, with whatever effect she wants it to have-and it doesn't stop there either. She asks for a magical Item Box, the ability to understand and speak every language, and the same body she had back when she was a fifteen-year-old girl.Using her newfound powers, Kaoru has to try and make a stable life for herself in a whole new world!

The second volume of an adventure with an earth-shakingly powerful Demon Lord (or at least someone who acts like one) taking on another world! After being summoned to another world that resembled the video game Cross Reverie, Takuma Sakamoto accidentally ended up with two girls as his slaves: the Pantherian, Rem, and the Elf, Shera. Takuma, under the guise of his screenname Diablo, came to this world a powerful Sorcerer, just like his avatar in the game. Along with the two girls and Emile, a devilishly handsome Warrior, they managed to protect the town of Faltra from the looming threat of invasion by the malevolent Fallen. But that peace they brought upon the town did not last long. The Kingdom of Greenwood, a country of Elves, makes a troubling demand: if their princess isn't returned to her rightful home within the time allotted, then the Kingdom will declare war on Faltra— And it's up to Diablo and the others to prevent a war with the Elves!

The third volume of an adventure with an earth-shakingly powerful Demon Lord (or at least someone who acts like one) taking on another world! After being summoned to another world that looks almost exactly like the MMORPG he once played, Takuma Sakamoto now spends his days going on adventures with Rem Galleau, the black-furred Pantherian, and Shera L. Greenwood, the Elf princess, both of whom accidentally became enslaved... to him!?One day, he is suddenly approached by the Fallen, Edelgard, with a request: Would he help her to undo the seal that keeps the Demon Lord Krebskulm inside Rem?Takuma, under the guise of his in-game character Diablo, hesitates, as he had previously made a promise to Rem to help her defeat Krebskulm- But he pushes through with his Demon Lord role-play and actually agrees!"I will revive the Demon Lord Krebskulm-and defeat them!"Now it's his Demon Lord role-play vs. an actual Demon Lord!

After receiving the power to create any potion she wants, Kaoru is sent off to live her new life in a brand new world. Things don't go exactly as she planned, though, and the truth comes out she's friends with the goddess Celestine!Though Kaoru tries to keep her head low despite this (emphasis on "tries"), she can't help but put her potion powers to use, drawing the attention of both countries she's already passed through.Now it's time for Kaoru to put her brand new schemes into action!