In the end, Akira got way too into his training and completely forgot the time.
By the time the stars filled the night sky, he still hadn't returned to their room.
So, when Erika came back and found it empty and smelled something burning, panic immediately hit her.
"...Akira?" she called out softly, looking around the darkened room. There was no answer. Only the faint scent of scorched wood, and maybe something that smelled disturbingly like roasted meat.
Her face paled. "...Oh no."
Good thing Selena contacted her telepathically right away. "Erika-chan, before you panic completely, he's fine."
"Selena," Erika muttered, looking around. "Where is he? What happened?"
Selena replied. "He's in the forest. Follow the scorch marks; he left plenty."
Erika dashed out of the Butterfly Mansion. Sure enough, when Erika rushed outside, faint burnt patches and footprints marked the grass leading into the woods.
As she followed them into the forest, Selena already filled her in on everything that had happened.
Running through the dark, she muttered under her breath, "Just how far did he run just to find water? There's a river right next to the Butterfly Mansion! Why did he go this far away!?"
Selena replied, her tone half-exasperated, half-amused. "Well, his new breathing technique is powerful. He probably blitzed past everything without realizing where he was going. Maybe his brain melted from the heat."
"His what!?" Erika exclaimed.
"Relax. It just heated up a little. No irreversible damage. Probably." Selena explained.
"'Probably'!? Selena!" Erika groaned, speeding up. "That idiot, he's always doing dangerous things! What am I even supposed to do when I find him? Scold him? Strangle him? …Ugh. Seriously, where even is he?"
Selena chuckled softly. "Why don't you try to sense him?"
Erika blinked. "Sense him? What do you mean?"
"Erika-chan, did you forget? His heart basically belongs to you now. You should be able to feel him if you concentrate."
Erika blushed lightly. "W-What are you talking about!?"
"I'm talking about the Sacred Gear, of course," Selena teased. "The one that's keeping him alive? So heart really does belong to you, hehe".
Erika pouted. "Why do you two always have to say it like that?"
"Because it's fun," Selena said cheerfully. "Well, it's fun for me. My brother sometimes does it without even realizing it."
Erika's eyebrow twitched. "...Wait, 'sometimes'? You mean other times, he does it deliberately?"
"Who knows?" Selena said in a sing-song voice. "I promised not to read his mind anymore, so I can't tell~."
"Yeah, whatever…" Erika muttered, though a faint flush remained on her face. "So, how do I sense him exactly?"
"Simple. Focus inward. You should feel a faint energy flowing from your body, something that connects you to him. Just follow that link."
"Got it."
Erika closed her eyes, steadying her breathing. The world around her faded into silence. She focused, and slowly, she felt it.
A faint pulse. Like a thread of light stretching outward from her chest into the distance.
It was warm. Familiar. Alive.
"…Found you," she whispered, and started moving.
The thread guided her deep into the forest until she reached the sound of rushing water.
When she stepped into a clearing, her eyes widened in surprise.
There, sitting beneath a waterfall, was Akira. Steam rose from his body, the water around him shimmering faintly as it cascaded down his shoulders. His expression was serene, meditative, like some ascetic monk from a martial arts movie.
Erika blinked. "…He's actually doing the anime thing."
She stepped closer, the cool water splashing gently against her legs. But she stopped short, her eyes narrowing in confusion.
"…Why is the water warm?"
"Warm?" Selena echoed. "Oh, that's nothing. It used to be boiling. This is a huge improvement."
"Boiling!?" Erika exclaimed.
"Yep. Don't worry, he's fine now. He's been working on this technique for hours; honestly, it's kind of impressive. Just wait a bit longer; I think he's almost done."
Erika folded her arms, sighing. "Unbelievable…"
So she waited.
A few minutes later, the temperature of the water began to drop rapidly. The warm water cooled to a refreshing chill, and steam faded away.
And at that exact moment, Akira's eyes snapped open.
He stood up slowly, water cascading down his shoulders, and suddenly threw his head back with an exaggerated laugh.
"Hahahahaha! Finally! After five thousand years, I have succeeded! I have become the strongest creature in the universe!"
Erika sweatdropped. "...It hasn't even been five hours."
"I just wanted to say that line at least once, okay?" Akira said with a grin. "But honestly, who has the patience to wait five thousand years? Besides, think about it! If a random stranger saw me right now, wouldn't they think I'm some ancient dragon awakening from eternal slumber?"
Erika sighed deeply. "Whatever. So… did you finish it?"
Akira nodded. "Yeah. It might need some fine-tuning, but it's functional enough for now."
"I see."
"What about you?" he asked. "Did you work on your breathing style? How did the EXP boost feel?"
Erika shrugged. "I don't know. It's only been a day, and I didn't notice much difference."
"Hmm, makes sense. Still, we should hurry. We're leaving this place in a few days." Akira said.
"Huh? Why?" Erika asked in shock.
Akira stretched, looking up at the night sky. "Because it's boring staying here. I want to explore this world, it's Taisho-era Japan, after all! I want to see it all. And besides, we still need to study demon biology and test some theories. We can't do all that cooped up here."
Erika nodded slightly. "That's true… but how are we going to travel?"
Akira froze. "…Good question."
He rubbed his chin thoughtfully. In this era, transportation options were limited. Only the rich had cars. Normal people took trains between cities, and if you wanted to travel freely, you mostly walked.
Akira grimaced. "There's no way I'm walking everywhere. We have to think of something."
Selena chimed in. "Why not build a car yourself?"
"I don't have the time, equipment, or money for that," Akira said flatly. "We're broke, remember?"
"Then join the Demon Slayer Corps for a bit. You can make some cash hunting demons," Selena suggested. "But as for transportation, I guess you're stuck walking."
"No," Akira groaned. "Walking that long is boring. If only I could use magic to fly…"
Erika smirked. "Too bad we can't fly here. Think of something else."
But Akira didn't reply. He just looked at her, intently.
Erika blinked. "...Why are you looking at me like that?"
"You can fly, right? You have wings. So why don't you just carry me?" Akira asked excitedly.
Erika stared at him flatly. "…Yeah, that's not going to work. I tried before. No matter how much I flap my wings, all I can do is glide."
Selena's voice came in, thoughtful now. "That's normal. Vampires and devils usually use magic to fly; the wings are just for control, not lift. The wings alone aren't aerodynamic enough for your body size."
"So basically," Erika said, "I can't fly here."
Akira smirked. "Not necessarily. You can use gravity magic, remember? If you manipulate gravity, you can fly."
"I've never tried that before."
"Then we'll just have to try."
"What do you mean by…" Before she could finish, Akira picked her up suddenly in a princess carry style and took off running.
No, blitzing.
"W-Wait! What are you doing!?" Erika yelped.
"Training!" Akira said cheerfully, leaping from tree to tree like a ninja from Naruto.
"Wait at least until we dry off! You're still wet!" Erika said, realising how Akira didn't even dry up after exiting the waterfall.
"Oh, right. Don't worry about it." His body heated up instantly, the air around them shimmering with warmth, and in seconds, both their clothes were completely dry.
Erika blinked. "…Okay, now you're just hot."
"Don't worry, it's temporary. I'll be cool soon," Akira said casually. True to his word, his temperature dropped back to normal moments later.
"Wait," Erika said, staring as trees blurred around them. "How are you running this fast!?"
"Simple," Akira said with a grin. "I'm using my new Breathing Style. Pretty effective, huh?"
"…I hate how casually you say that."
Soon, they reached the top of a mountain, the wind whistling around them.
Erika frowned. "If you even think about throwing me off, I swear I'll never forgive you."
Akira smiled innocently. "Don't worry. I'd never throw you."
Then he promptly walked to the edge and jumped.
"AKIRA!!!" Erika's heart stopped. Without thinking, she leapt after him, spreading her wings mid-fall and catching him in her arms.
"WHAT THE HELL IS WRONG WITH YOU!?" she screamed.
Her wings flapped hard, slowing their descent, but not enough. They were still falling, fast.
Selena's voice rang urgently. "Erika-chan! Use your power! Your device!"
Erika panicked but summoned her red ribbons anyway. They shot out from her wrists, shimmering with energy, but she still didn't know how to use it.
"Gravity is your domain, not your device's," Selena said sharply. "Use it!"
"I swear I'm going to kill him after this!" Erika muttered furiously, channelling her power. Magic surged through her veins as she bent gravity's pull, lightening their bodies.
Magic energy surged through within her, and suddenly, her wings caught the air.
They stabilized. Then, they soared.
Akira laughed lightly, watching the stars above. "You did it! I knew you could!"
"WHAT IS WRONG WITH YOU!?" Erika yelled again, furious. "WHY WOULD YOU DO THAT!? ARE YOU OUT OF YOUR MIND?"
"Because I believed you'd save me," he said simply.
Erika fell silent, heart pounding.
"…You idiot," she whispered.
"Well, even if you didn't, I probably would've survived with my armor and acrobatics," Akira added.
Selena sighed. "Wow, brother. You really don't know when to stop talking."
"What do you mean?" Akira asked telepathically.
"You'll see."
Moments later, Erika landed roughly on the ground and set Akira down.
"Well," Akira said with a nervous laugh, "that went well. Let's do it again—"
But he froze.
Erika stood silently, tears welling in her eyes.
"E-Erika? Why are you crying? What happened?"
She said nothing.
Selena's voice sighed in his mind. "What did you expect? You terrified her, you idiot. She's scared and angry."
"I just thought it would be fun…" Akira mumbled weakly.
"Fun!? She has a heart, unlike you. Apologize." Selena said in an exasperated voice.
Akira quickly turned to Erika. "I'm sorry! I thought it'd be fun, I didn't mean to scare you!"
Erika wiped her eyes quietly.
"I'm really sorry! Please don't cry! I promise I won't do that again!" Akira said in a soft voice.
Finally, she spoke softly. "...You scared me."
"I know. I'm sorry. I'll do anything. Just… don't be sad, okay?" Akira said.
There was a pause. Then, without warning, her red ribbons flared.
They wrapped around Akira in an instant, binding him tightly into a cocoon, only his head sticking out.
"Huh," Akira said blankly. "You can control it really well now."
Erika's tone was calm, too calm. "You made me mad. You need to be punished."
Akira blinked. "Okay, fair. What's the punishment?"
The ribbons tightened slightly, crushing him just enough to make him squirm.
"Erika?"
"Come," she said simply.
The cocoon floated beside her as she turned and started walking back toward the mountains.
Akira had no idea what she was planning. He only hoped it wouldn't be too bad.
Erika, meanwhile, was lost in thought.
When Akira had jumped, her heart stopped. She'd been terrified, truly terrified. But after seeing his panic when she cried, and how quickly he apologized, she couldn't stay angry for long.
He didn't mean to hurt her. He just didn't think. Selena had warned her before that staying by his side wouldn't be easy.
She sighed softly.
Still, she couldn't let him get away with it.
She glanced at the floating cocoon beside her and smiled, a cold, dangerous smile.
"I'll forgive you," she said sweetly. "But you have to do everything I ask of you, while we're in this world. Deal?"
"Y-Yeah! Anything!" Akira said instantly.
"Good."
Selena's voice laughed quietly in Erika's mind. "You know, you're the only person besides our family that he lets punish him. Use that power well, Erika-chan."
"Oh, I intend to," Erika replied with a smirk.
That night, they trained to fly together until late under the starlit sky.
And for the next few days…
No one saw Akira.
Only Pan-chan appeared, obediently floating everywhere beside Erika, suspended by her red ribbons.
No one dared to question it.
And for some reason… everyone just quietly accepted it.