Mitou Shoukan://Blood-Sign - Volume 8, Battle Tutorial

Arthur got randomly transported to another world. Some people would find that terrifying, but not for him, who was tired of his old life; it was an opportunity.

And, after having bad luck all his life, the tide changed.

It was a world of magic where wizards fought side-by-side with their familiars. Arthur got summoned to be one of these so-called familiars.

He was furious. The thought of becoming a pet was not something he liked. Well, that changed when he saw who his master was.

A hot-woman. And, to make everything better, Arthur was inside the Frostpeak Magic Academy, which only had women students.

“This is heaven. All familiars are beasts, but I'm different. I'm a good-looking man inside a place filled with hot girls.”

When he thought his luck could not get better, he unlocked a system that helped him with everything. Of course, he used the system for a greater good, like getting girls.

I wanted to rely on hard work and hard work to become stronger, but I found that lying down is more comfortable.

The point is, you can upgrade while lying down!

Why should I stand when I can lie down?

- Description from novelbuddy

#Rated 18-Mature ThemesViolet’s life was never her own—her father’s crushing debt made sure of that. But when the debt collector kidnaps her as payment, she takes a desperate deal: become a servant and spy on the mysterious and tyrannical Lord Cain, the ruler of her Werewolf district.There’s just one catch: Lord Cain only permits male servants in his house.Disguised as a boy, Violet cuts her hair, flattens her chest, and dons a voice-altering band to pull off the deception. Everything goes according to plan—until Cain, a man known for his cold personality starts to take a peculiar interest in her.Violet’s disguise becomes a prison as she battles her own growing attraction to him. But this is no love story. Cain’s obsession to her is dangerous. Beneath his icy gaze lies a mind fractured by years of affliction by a curse.A curse made by Violet's biological mother: A powerful witch.*************“TAKE IT OFF!”Violet’s knees nearly buckled at the thunderous command, her chest tightening with panic. The raw anger in Cain’s voice was as sharp as a blade.“My lord! I-I’m a man!” she stammered, gripping her shirt tightly, her fingers trembling as they clung to the fabric.“I don't like other men!” she cried, a desperate plea in her voice since the second she took her shirt off and he discovered that she was a woman was the moment she died. Painfully.Cain’s glare was unyielding, his voice dropping into a growl. “Don’t insult me, You think I do. You kissed me!”Her breath hitched as he stepped closer, his presence suffocating. “If you don’t take it off,” he said, his tone low and dangerous, “I’ll rip it off myself.”Violet’s mind raced, panic threatening to overwhelm her. She couldn’t let him find out—he’d kill her. Painfully.Glancing away to avoid his gaze when she caught the undeniable bulge in his trousers. Heat flushed her face, her thoughts spinning in desperation at the only idea she could think of to make him back off.'This has to work. It has to!'

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.