Charlotte Evans, a young lady accused of treason is rescued in the forest by the reclusive Demon Lord, Allen Crawford. Hiring her as a live-in maid, Allen plans to teach Charlotte about everything "naughty" in the world. First up: eating cakes for dinner!

Allen's second naughty lesson involves an item delivered by Miacha, a courier from Satyros Shipping Company. What is Allen's naughty way to release stress?

Eruca Crawford, Allen's step-sister, suddenly appears to try to drag her brother home. The day quickly turns into a no-holds barred competition when the siblings challenge each other to see who can teach Charlotte the most naughty things in town.

Charlotte asks Allen if she can go to town alone for shopping. Concerned, Allen, Eruca, and Miacha secretly follow her to make sure she is okay. But Charlotte ends up in an unsafe area, and bumps into a dangerous party called Serpent Fang.

As a gift from townspeople, Allen and Charlotte visit Yunoha Resort. But it turns out to be a lovers' retreat, arranged by Eruca and Miacha. Soaking in a hot spring in swimsuits, sleeping in the same room... Their relationship rapidly develops.

Lü and Gosetsu start living at Allen's mansion. Allen is happy to see that Charlotte has a new goal of becoming a magical creature tamer. One day, they're shocked to see a small-built girl emerge from the basement, who turns out to be...!

Allen's mansion's former owner, a dark elf Dorothea, asks Allen and Charlotte to play skits in exchange for the mansion. Since they're forced to play lovers, Allen and Charlotte begin to see each other in that light.

Hearing that Charlotte's little sister is in trouble, Allen and the others rush over to Allen's hometown. They're welcomed by Allen's uncle, Harvey, and his aunt, Liselotte. As they figure out Natalia's situation, they're forced to pretend being lovers.

Allen brings Charlotte in disguise to check up on Natalia at the academy. At the tender age of 8, Natalia has become the head of the group of thugs, constantly fighting those around her. Allen has come up with a solution to her problems.

Hiding her identity, Charlotte spends a great time with Natalia. But Chris steals Natalia's precious bag out of bitter rivalry toward her, and lures her into a dungeon where entry is forbidden.

Natalia and Chris have stepped into an off-limit dungeon. Charlotte rushes to their rescue, but her strength isn't enough to save them all... Will Natalia finally find out who Charlotte is? What happens to Allen and Charlotte?