Risou no Himo Seikatsu - Volume 3 Chapter 3

A Federation Colonel with abnormal thoughts was locked in a dark room and met a little looney.

“Your whole body emits a scent that I dread (covet) and fear (desire).”

A frigid Colonel X little looney roommate: A sweet story of interstellar travel

- Description from Novelupdates

At the age of 12, Shen Yue accidentally fell into a pond while feeding fish. That’s when she realized that her parents were not her real parents, and her five brothers were not her real brothers either. She was just a fake heiress to the Shen family!

Knowing she was destined to lose everything, Shen Yue decided to just lie down and give up. If she was going to lose it all anyway, she might as well just lie down and relax.

“Big brother, is working at the company fun? Let me check it out,” she thought, wanting to enjoy the perks of being a Shen daughter while she still could. Those luxuries would be out of reach soon enough.

“Second brother, is acting fun? Let me give it a try,” she schemed. What? They pay you just to lie still like a corpse? This is a job she had to get!

“Third brother, is that gun realistic? Let me see,” she said, examining the firearm. Not bad, though the recoil is too strong. She’d need to find a smaller one to play with next time.

“Fourth brother, will the teachers be mad if I sneak into your research institute? Let me take a peek,” she plotted, eyeing her handsome professor. A little hugging wouldn’t hurt!

“Fifth brother, that medicine you’re working on smells nice. Mind if I try a little taste…” she asked casually before sampling it. Tastes good! But now my head feels itchy—I better not be growing a brain!

On the day the real heiress returned, Shen Yue’s five brothers shielded her behind them. “Dear sister, can we keep her with us? She’s a bit slow, it’d be dangerous for her out there alone.”

The true heiress scoffed coldly, masking her sly intentions beneath a guise of innocence.

But in the end, she realized this Shen Yue really was quite dim-witted. Oh well, might as well let her stay.

After dying a pathetic death as an overworked office drone, I woke up reincarnated as Archer—the bastard prince of the Brutish Empire.My existence is a royal secret as My father, the King, would rather pretend I don't exist. My half siblings get royal treatment while I'm hidden away like a dirty secret.But I have a secret of my own. I was OP.By age two, I realized monsters flee from my stupidly OP mana. By age ten my mana could level cities—if I dare to unleash it.When my half-sister is kidnapped by the demon king, I finally decided to step out of hiding to become the strongest in this new world.

Lyle Walt is a young noble boy and heir looking forward to the day he can inherit his family’s territory. Except around when he was 10 year old, his parents started neglecting him more and more in favour of his little sister, Celes.
On his fifteenth birthday, he is challenged to a duel by his sister to see who will inherit the household and horribly loses, being cast out of his family. Afterwards, he gets treated by the family groundskeepers and receives the family heirloom Gem from him that Lyle’s grandfather had entrusted to him. From there, he begins an aimless journey with his childhood friend and former fiancée, Novem, and the Gem-turned-Jewel that houses the memories, personalities, and Skills of seven of his ancestors.