Sword Art Online - Vol 1 Chapter 17

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.

When The Cute Kunoichis Spied on Their Teacher's Secret is a light novel written by Kazuma Kamachi and illustrated by Ryuushi Tajima.

The story takes place in a world where Japan never ended their isolationist phase, and agents from foreign powers are always threatening to steal the country's advanced technology. In order to combat this threat there has been a resurgence of ninjas that use Strategic Martial Arts, techniques that combine cutting-edge modern technology with a traditional foundation of martial arts and ninjutsu. The story follows Souha Sugiyado, a 17-year old ninja instructor and former ninja prodigy who was forced to retire from active duty by the wounds he suffered in his last mission. Souha's four students are all kunoichi who have all gained the rank of Elite Ninja, the highest official rank available to ninja. However, one day two Shogunate ninja approach him with the news that his four students have gone rogue and have stolen a portable modular nuclear reactor, and thus they ask for his help in bringing his students to justice.

Okay, so I know I applied to become a caretaker, but I didn't sign up for having to experience all these crazy things! I'm just a simple guy!

My surname is Wu, and everyone calls me Xiao Wu.

Listen, brother, here are some of my experiences-

Don’t listen to what it says when you fight with the dragon, just fight until it dies;

It’s a little more troublesome to beat the goblin, it’s better not to let it see you, you have to shoot the black gun;

It’s a word to engage in orcs, naked!

If the devil dares to come to trouble, he will break his horns, and he will kneel;

Okay, I’m going to fight at the bar now, I’ll write more about the introduction when I get back

- Description from novelbuddy