The Dutiful Kid Who Saved the Villainous Family

Airi, a lively 5-year-old child raised lovingly by her grandmother.
One day, after collapsing from overeating and waking up…
She suddenly remembered her past life as a righteous K-child (a Taekwondo belt-holder)?
“Wait, I’m supposed to save the world?!”
No problem, I can totally do this!
Starting with these naughty kids!
“You can’t speak to your friend so rudely!”
“What? Ha! Like a tiny little thing like you can do anything…”
So, I delivered the ‘Hectopascal Kick’ I learned from Master Kyung-hye at the Taekwondo dojo.
“Aaagh!”
“Don’t mess around!”
That’s right.
This former K-child was strong (physically).
Very, very strong.
Declan Ortezo (33), the mighty (and villainous) Grand Duke who governs the northern region.
The youngest daughter, Airi, whom he met again, seemed highly suspicious.
“Please take good care of me, elder.”
…Am I not your dad, but ‘elder’ to you now?
And when I tried to warn her about her reckless behavior—
“I’ll make you eat broccoli. And the bitter, awful-tasting mugwort, too!”
“Gasp! I love broccoli so much! And mugwort smells delightful!”
Her tastes were way too mature for a child, making it impossible to reason with her.
“I trust you’ve been well, my dear father?”
“Ah, you even know proper etiquette. As expected, you’re so smart…
…Both Grandma and Grandpa looked at her with pride and satisfaction.
No, is it just me who finds all of this strange?