That day, just like always, Leo's group and Rias's group, including Sona, finished school and used the magic circles in their homes to teleport into the separate dimension for training.
But when three magic circles appeared at the same time and everyone stepped out, they found someone already there.
A guest.
In a space that shouldn't have been accessible to outsiders.
"So-tan~~~!"
A teary, overly dramatic cry rang out. Before anyone could react, a blur shot forward at terrifying speed and threw herself at Sona, wrapping her in a tight hug.
Everyone froze.
The girl clinging to Sona was a stunning beauty.
She didn't have Rias's mature, voluptuous charm, nor Sona's slender, icy elegance. Instead, she looked like she'd stepped straight out of a fairy tale. Innocent, bright, overflowing with energy. Just standing there, she radiated cheerfulness.
Her looks rivaled Rias and Sona easily, delicate and cute. She wore a JK uniform and looked every bit like a high school idol who could suddenly jump onto a stage and break into a lively dance.
Right now, that "idol" was hugging Sona tightly and rubbing her cheek against hers.
"Sona! My Sona! Big sis missed you so much! I've been wasting away without you!"
Sona stood there like a doll, stiff as a board.
Her usual cool, rational composure was gone. Panic flickered plainly in her eyes.
"S-Sis?"
It took her several seconds to get the word out.
"W-Why are you here?"
Even Leo's eyelid twitched. He'd half a mind to turn around and walk away. He absolutely hadn't expected her to show up here.
"Who is she?"
Some of the servants who didn't recognize her exchanged confused looks.
But sharper minds like Yukino, Utaha, Asuna, and others immediately pieced it together.
"Sona-senpai's… sister?"
That was how the girl introduced herself. And Sona had called her "Sis."
And Sona Sitri only had one sister.
The strongest female devil in the Underworld. The only female Maou among the current rulers. The absolute authority in diplomatic affairs. Born of the Sitri House, yet inheritor of the name Leviathan.
Serafall Leviathan.
"Y-You're Lady Leviathan?!"
The girls gasped.
"Leviathan? Huh? Huh?!"
Issei and Saji reacted a beat slower, then stared in shock.
"S-She's the strongest and most beautiful female devil in the Underworld? That Lady Leviathan?!"
Issei practically shrieked.
Ever since becoming a devil, he'd been fantasizing about meeting this legendary female Maou. In his imagination, she was a sultry, captivating older sister type with a killer figure and seductive lips that made every word sound enticing.
Instead…
This was a hyperactive, adorable high school girl?
The gap was insane.
"'Strongest and most beautiful' is just what other people say." Serafall hugged Sona like a giant plushie, looking both shy and delighted. "I'm just a cute magical girl. Don't call me Leviathan, call me Levia-tan instead~~"
Leo nearly groaned.
Even knowing her personality, seeing it in person still made him want to complain.
"Magical… girl?"
Yukino and the others looked completely lost.
Ravel, as a pureblood devil from a noble family, seemed more familiar with Serafall's reputation.
"Th-That's just Lady Serafall's personal hobby…" she said awkwardly. "Her Majesty really loves magical girls from the human world, so she identifies as one."
Silence.
A Maou.
Calling herself a magical girl.
Was that really good for the Underworld's image?
Everyone silently screamed inside.
"It's been a while, Serafall-sama."
Rias stepped forward and bowed politely.
The others quickly followed suit.
"Long time no see, Rias~~"
Serafall greeted her cheerfully, her voice sweet enough to rot teeth. There wasn't a trace of Maou authority about her.
"Sis! You still haven't explained why you're here!"
Sona finally managed to move and tried to pry herself free.
"I came to see my So-tan, of course!" Serafall refused to let go, easily restraining a High-Class Devil with what looked like delicate arms. She puffed her cheeks in mock anger. "You barely contact me! I had to take advantage of this chance to visit the human world!"
She hadn't been able to sit still lately.
Twice now, her beloved little sister had nearly been killed. Once during the Old Maou Faction's attack, and again when Kokabiel showed up.
Both times, the targets had been the Maou's younger sisters, Rias and Sona.
If not for her responsibilities, she would've rushed over immediately.
Now, with the three-faction summit approaching and her attendance confirmed as the Underworld's diplomatic representative, she finally had an excuse to come.
As for entering this separate dimension?
It had been created by the Maou, led by Sirzechs, for Leo's group. If others couldn't enter, surely the creators could.
So she came. And waited.
Unfortunately, Sona didn't look thrilled.
"I contacted you not long ago," Sona said stiffly, her dignity clearly crumbling in front of her servants. "And how many times have I told you? I'm not a child. Stop calling me 'So-tan.'"
"It's my special nickname for you!" Serafall huffed. "It shows how close we are! Everyone will be jealous!"
"W-Who's jealous?! Stop making up weird storylines!" Sona struggled again. "And let go of me, Sis!"
"Nope! I'll never let go of So-tan! Not for the rest of my life!"
"Let go!"
"Nooo! Don't leave Big Sis, So-tan!"
"I said stop calling me that!"
"So-tan's so cold~ Come cuddle with Big Sis~~~"
"Ah! Sis! Where are you touching?!"
The two beauties twisted together in full view of everyone. The atmosphere was getting dangerously close to R-rated.
Several of the girls blushed.
"Gulp."
Issei and Saji stared with shining eyes, swallowing hard.
When Sona let out a sharp yelp and Serafall's hand wandered somewhere it definitely shouldn't have, their breathing grew heavy.
I wish I were that hand!
Before their delusions could go any further...
Thud!
Koneko's fist slammed into Issei's stomach. He doubled over, eyes bulging as spit flew from his mouth.
"And you, Saji?"
Tsubaki smacked Saji hard on the back of the head, sending him face-first into the dirt.
"H guys are the worst."
Koneko calmly stepped on Issei's head, grinding it into the ground.
"Ahaha…"
Kiba had turned around the moment Serafall and Sona started wrestling. Hearing the chaos behind him, he could only laugh awkwardly.
As for Leo?
He watched openly.
None of the girls dared stop him.
"You show me this and expect me to stay bored?"
That was what he wanted to say.
Seeing his blatant interest, Yukino and the others shot him disdainful looks.
Then Serafall noticed him.
"Ahhh...!"
The Underworld's only female Maou reacted like she'd just spotted her mortal enemy. She rushed over and planted herself in front of him, hands on her hips.
"You annoying jerk! I knew you'd be here!"
She pointed at him, puffing up in outrage.
Adorable outrage.
But Leo knew better.
She might look cute, but she absolutely held grudges.
Out of jealousy, because of how close he was with Sona, she had definitely targeted him before.
Running was pointless. Even if he tried, she'd catch him.
Serafall was a Super Maou-Class powerhouse. According to Sona, she could freeze someone like Kokabiel ten times in ten seconds, precise down to one freeze per second.
Even now, Leo could probably only defend himself at best.
So he gave up escaping and put on the fakest smile imaginable.
"Hello, Serafall-sama. Long time no see…"
The perfunctory tone was obvious.
"Hmph! Levia-tan doesn't want to see you at all!" she snapped. "You wicked scoundrel trying to steal my Sona! Hiding here won't save you. Wherever my Sona is, I'll be there!"
"Yes, yes. You two are inseparable," Leo replied dryly. "Being called a scoundrel by a female Maou makes it sound like I committed some unforgivable crime."
"Haven't you?" Serafall shot back without hesitation. "Following my Sona around all day, what could be more unforgivable?"
"Don't make me sound like a stalker," he said, mouth twitching. "And I don't follow her around all day."
"I don't believe you!" Serafall declared firmly. "My So-tan is so cute. Even I want to follow her everywhere. How could a bad man like you not want to?"
If anything, aren't you the worse one here?
Leo decided it wasn't worth saying out loud.
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You can read up to chapter 229 on patreon.com/NiaXD.