Starting With The Sefirah Castle In The Anime World - Chapter 15 - : “Kaguya” Locked In

He approached her and announced domineeringly, “Ten million, you're mine!” Little did he know that she would smash his head and flee in panic! Five years later, for the sake of her young son, she endured humiliation and became his wife, always on guard around him, “Get out, what are you doing coming in?” His handsome face darkened, “Woman, you couldn't have forgotten that we are husband and wife, could you?”

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

After centuries of ruling the underworld with terrifying power, Lilith dies in an epic battle, only to be reborn in the human world. But instead of a grand rebirth as a queen of darkness, she's reincarnated as something far more mundane—a secretary. Rather than despair, Lilith finds this new life amusing. After all, who would suspect the devil herself to be working a 9-to-5?Settling into her new reality, Lilith embraces her role, living in a luxurious apartment and working diligently in her office. Though her devilish instincts are hard to suppress, she's determined to be the perfect secretary. But when people push her too far, the devil within still comes out to play.When a creep in the office dares to look at her the wrong way, she calmly fixes her gaze on him. “You keep staring like that, and I'll show you what a broken wrist feels like.” The man quickly scurries away, leaving Lilith with a satisfied smirk.Even the rich, entitled girl from accounting isn't safe from her wrath. “You think you can push me around just because you've got money? I've burned entire kingdoms for less. Don't test me.” She says this with a calm smile, her eyes glinting dangerously.The day continued like that—stopping creeps in their tracks, putting rude heiresses in their place, and being the flawless secretary she intended to be. But, of course, her boss—the CEO—had his eyes on her, more curious than ever. And while the entire office might fear her or wonder about her, she remained blissfully indifferent. This was fun. And she wasn't here to impress anyone but herself.Who knew being a secretary could be so... interesting?

An 18-year-old girl who lost her family in an accident, Yamano Mitsuha falls off a cliff one day and transferred to a different world with a civilization level of medieval Europe. Mitsuha who discovered it was possible to go and return to Earth after a deadly fight with wolves decided to live in both worlds.

「For the sake of security in old age, I will aim for 80,000 gold coins!」

I will try not to let strange things circulate and distort the progress of the world, but I won’t hold back for the sake of my easy life and safety! While carrying three handguns along with words and deeds that appear decent, in her head, Yamano Mitsuha is a sly girl.

Making an effort to make money even with a small body that looks like a child to foreigners!

Oh, my secrets are too dangerous, you said? It’s fine, it’s fine! I’ll transfer away when push comes to shove!