The noise came from the classmate who sat in front of Ange and next to Mutsuki.
Without speaking a word, she grabbed her bag and stood from her seat as if to throw cold water on the volatile situation.
Compared to the girly Lucia or the manly-eyed Ange, this girl's sex was much more obvious. Her facial features were as flawless as a doll's and her glossy lips were the pink of a sweet springtime dessert. Her slender limbs and the height of her hips gave her a refined and almost artificial-looking beauty.
Her name was Ibekusa Machina. Barely anyone had held a proper conversation with that silent and mysterious classmate.
She was the one person in the class that Ange had to be cautious around and forced her to restrain her short temper.
And to Mutsuki…
"Oh…Um, Ibekusa-san."
He called out to the girl as she started to leave.
When she faced him, her transparent – too transparent – and unreadable eyes made his heart race, but he gathered the courage he had finally gained recently.
"See you tomorrow."
"…See you."
He had managed to say goodbye.
Machina left after a short response and Mutsuki watched her leave with his cheeks relaxed.
That short exchange was all he needed.
He had been interested in this classmate since the spring. Until recently, he had never even spoken to her, but now he could greet her like that. He was happy with just that.
"Nnn…"
"…Honestly."
Behind him, Lucia grimaced jealously and Ange formed an even more lopsided frown.
"Um…"
The two of them walked out the school gate side by side.
"The pool opens tomorrow, doesn't it? That'll be a first for you won't it, Ange? Do you even have a swimsuit?"
"…"
Even though they walked home together, it was hard to say they got along.
"You do understand, don't you?"
After entering a back alley so they could not be seen, the silent girl exploded with irritation. Mutsuki had half expected this and she crossed her arms while glaring arrogantly at him.
"Don't tell me you've forgotten why I'm here."
"O-of course not."
"The higher ranking angels do not wish to infringe on your freedom. Leaving your home is enough stress on its own, so we aren't telling you to change your name, change your school, and hide in some distant part of the world. I am protecting your current lifestyle by acting as your bodyguard."
"Yes, and thank you."
"But how am I supposed to protect someone so stupid he makes friends with the enemy!?"
She gave him an incredibly menacing look as she shouted in anger.
She was less than 140 cm tall and she had an adorably childish face (except for the eyes), but she still had the intensity of an experienced hero.
Jiyuuni Ange was said to be the most powerful angel.
And then there was "the enemy" she referred to.
Mutsuki had hardly forgotten why Ange was here and why she was acting as his bodyguard so he did not have to leave his hometown or school.
That was the biggest trouble that had arrived in Fujita Mutsuki's life: the Serpent's Eye.
Some called that dreadful power the ability to rule half the world. One month ago, Mutsuki had learned it resided in his body.
When activated, that demonic eye could make slaves of half the world. That is, the female sex of man, beast, angel, demon, and all living creatures.
Any woman viewed by that corrupting demonic gaze would be filled with sexual arousal.
Thanks to that power, Mutsuki was being targeted by FeTUS, a human group that used mechanical soldiers, and the demons, a collection of supernatural creatures.
If misused, that power could fundamentally destroy the order of the world, but there was another group that protected it.
Those were the angels.
They were servants of order and they would nip any sign of disorder in the bud.
Currently, Mutsuki was being protected by them.
He had left his home to keep his family from being caught in the middle of it all and he was living with two angels. Ange of the Double Flame was his dedicated bodyguard, so she even came to school with him.
FeTUS and the demons were frightening opponents, but the angels were reliable and the first three weeks had passed without issue.
It was ten days ago when things had changed.
He had thought Ibekusa Machina was a perfectly normal girl who had been his classmate since the spring, but he had since learned she was a member of FeTUS.
For some reason, she was not targeting Mutsuki. Ever since spring, she would have had countless opportunities, yet she did nothing but observe even as he grew closer to her.
Ange and Mutsuki had tried to ask her about it, but the second incident had interrupted. A demon had joined their class as well. That was the coquettish transfer student, Satowa Lucia.
They could not tell what he was after either. And with an angel, human, and demon present, all three were unable to act.
Angels were born from a pure radiance and were formed from the purifying light that was fire. They had the power to burn away the impure creatures that were demons, but as their temperature only reached 1000 degrees Celsius, they could not burn away machines with a metal framework.
Those human machines were resistant to heat, but tools that could not autonomously evolve had a limit and could not handle the constantly evolving demons.
As an ever unknown existence, the demons had an advantage against the human knowledge based on past data, but they were weak against the holy blades of heaven.
The three of them were in a three-way deadlock.
Angels were strong against demons, demons were strong against humans, and humans were strong against angels.
With a representative of heaven, earth, and hell next to the ultimate power that was Mutsuki, they all held each other in check.
A three-way battle that could influence the entire world could break out at any moment, but ten oddly peaceful days had passed.
"How many times do I have to tell you that making friends with FeTUS and the demons is out of the question?"
"I know, I know."
The two of them chose a deserted way home and Ange expressed her irritation the entire way.
That was hardly surprising. Two unreadable enemies were constantly nearby and she could not do anything to them. Nothing could build up more stress for a bodyguard.
Plus, Lucia liked to cling to Mutsuki, Mutsuki was too nice to be mean, and they ended up simply looking like friends.
"Listen, Mutsuki."
"Yeah?"
"I don't know why they're behaving, but keep in mind that they'll pluck your eye out the second you let your guard down."
After receiving that frightening warning, the boy hung his head.