On his way back, Riku took a few bites out of himself. Each chomp was hard and deliberate, and naturally, some accidents happened along the way. Like, say, swallowing a few gulps of his own blood or tearing off chunks of his own flesh. Yeah, that actually happened on the road.
"Could it be…?" Riku swallowed hard, pulling up his [Personal Page] again to check the description of his newly optimized "Kyokushoku" ability.
Kyokushoku: In addition to human flesh, you can now consume oni flesh.
Reading it literally, Riku was certain he'd stumbled onto a bug in the system.
"No, wait, this isn't a bug—it's a feature!" he declared, quickly adapting to the situation. If it worked in his favor, it was a feature. If it screwed him over, then it was a bug. Classic ninja logic, like something Naruto would grin about while dodging a trap.
Crunch.
Lost in thought, Riku took another bite out of his forearm. He wolfed down the flesh like a starving shinobi, and sure enough, his hunger eased up. He'd already chomped himself too many times on the way back, so now, as he tore off a big chunk and chewed while watching the wound heal, he didn't even flinch.
He was getting used to the pain, which was a good thing. The sooner he adapted, the better—because who knew how long he'd have to keep eating himself to survive? If every meal was agony, that'd be torture. Not that it didn't hurt now, but still.
"The taste is… bland. Compared to the scent of human flesh, this is like chewing wax," Riku muttered, giving his review after a few bites. He hadn't actually eaten human flesh, but just the smell was enough to know it was on a whole different level. The "oni flesh" he was eating? Zero appeal. If it wasn't for that, he'd have figured out this system "feature" way sooner.
"Food's food. No need to complain when you've got something to eat," he said, channeling a bit of Naruto's grit. Left arm, right arm—he took turns biting until his stomach was full. The only cost? Some pain.
Sometimes, when he ate slowly, the previous bite's wound would already heal before he could take another. It was like a perpetual motion machine—regeneration so fast it defied logic. As long as he didn't push his regeneration to its limit, food wouldn't be an issue anymore.
"This system feature? Ten out of ten," Riku said, grinning. With his hunger satisfied, his mind felt sharp again, like a ninja ready for the next mission.
He grabbed a handful of snow outside the cave to wash the blood off his face, then prepared to head back to the "crime scene." He remembered there was a little girl in that family who wasn't dead yet. He had to check on her.
To keep himself in check, he'd stuffed himself to the brim this time. Surely that'd stop him from being tempted by all the blood and flesh, right?
Following his markers, Riku set off again, glancing at the sky. Dawn was still a while away. His earlier trip, plus "dinner time," took maybe five or six hours. It was probably one or two in the morning—plenty of time for a round trip.
The snowstorm had calmed down by now. It was already slowing when he'd returned earlier. Following his markers, Riku soon arrived back at the wooden cabin.
This time, his head was clear, and he noticed something he'd missed before. The cabin wasn't alone—there was another building nearby, probably a woodshed. This family likely made a living chopping firewood, a simple life like the villagers in the Land of Fire.
Pushing those details aside, Riku approached the main cabin and stopped at the door.
Gulp.
Even stuffed, the scent of human flesh was still mouthwatering, but at least he could control himself now. He looked at the doorway. A girl in a pink kimono lay there, covered in blood, as if she'd been trying to shield an even smaller child beneath her. She'd failed.
"…" Riku fell silent. In his hunger-fueled haze earlier, his judgment had been off. There were no survivors here. The only "living" thing was an oni—this girl had been turned.
He peered inside. A mother had desperately tried to protect her children. Another daughter lay dead behind her. The two boys in the family had fought bravely, giving the girl at the door and the youngest child a chance to escape the cabin.
"Something's off," Riku muttered. "No bite marks on the bodies, and one was turned into an oni. Can a regular oni even do that?" He didn't know if other oni could, but he sure couldn't turn anyone into an oni. And wouldn't a typical oni at least take a nibble in a situation like this?
His expression shifted as the pieces came together, pointing to one answer. "Was this Kibutsuji Muzan's doing?" he wondered aloud, stepping inside to sniff the air. But the overwhelming scent of human flesh drowned out everything else. His nose wasn't sharp enough to pick up Muzan's trace—like trying to sense chakra in a storm.
"Forget it. Better get out of here," he decided. Even without proof, he wasn't taking chances. Better safe than sorry, like dodging an ambush from the Akatsuki.
But then he paused, looking at the motionless "oni girl" still lying at the door, showing no signs of waking. "What do I do with her?" he muttered, conflicted. "Poor kid. Family slaughtered, turned into an oni… but I can't just leave her like this. Should I… kill her?"
As a regular guy from a peaceful modern era, Riku had never killed anyone. Heck, he hadn't even killed anything bigger than a freshwater fish. Killing someone—or something—felt like a huge leap. But this "oni girl" wasn't human anymore, right? More like a "humanoid creature."
Still, she looked way more human than he did. That made it harder.
After two seconds of hesitation, it hit him—oni only die to sunlight, and he didn't exactly have the means to kill one. "Except by eating…" He glanced at the girl, gritting his teeth. No way he could stomach that right now. And even if he could, eating a living target? That was a line he couldn't cross.
Hunger made you reckless, but a full stomach made you think too much. If he was still starving, he probably wouldn't be agonizing over this.
"I can't just leave her," he decided. "Let the sunlight handle it."
He rummaged through the cabin and found some sturdy rope. Effortlessly lifting the "oni girl," he tied her securely to a post in front of the woodshed. No way she'd break free.
"Sorry, kid. This is the best I can do," Riku sighed. Hanging her here would keep her from hurting anyone else. Surely, she wouldn't want to become a monster either.
"If I get the chance, I'll avenge you," he promised. He felt for this family—their bond, their desperate fight to protect each other. As an orphan, Riku envied that kind of connection. It's why he was going through all this trouble. Living in this remote mountain forest, they must've been happy, right?
With that done, he didn't linger. Following his markers, he hurried back to the cave. Staying in the cabin might block the sun, but being surrounded by "gourmet food" was too much for his self-control. Plus, the cave felt safer. If someone found him with a pile of bodies, there'd be no explaining that. They'd probably just burn the cabin down and leave him to fry. But in the cave? Good luck moving a whole mountain to get to him.
By the time he reached the cave, the sky was starting to lighten. Winter days meant early sunrises.
"What a night," Riku muttered, leaning against the cave wall. He summed up his haul: discovered a system feature, solved his food problem, and learned that Kibutsuji Muzan might still be lurking nearby. No progress on "how to level up," though. Not his fault—he hadn't run into a single living thing, except for an oni he couldn't kill.
"Here's hoping that oni girl gives me some experience when the sun takes her out. I mean, I put in the work, right?" he said, indulging in a bit of fantasy. He didn't know how the [Ultimate System]'s experience worked, but maybe it'd count.
"Whatever. No point stressing over things I can't control. No hunger today, so I can't just sleep the day away. Time to get to work!"
Pushing the daydreams aside, Riku stood up. He couldn't go out in the daylight, but that didn't mean he couldn't do something in the cave.
"Alright, let's do 100 push-ups, 100 sit-ups, 100 squats, and a 10-kilometer run!" He glanced at the cave's size. "Okay, scratch the run. I'll do it in place."
"Train hard! Keep pushing! Even with a system, you can't slack on self-improvement!" he said, hyping himself up like Naruto before a big fight. Sure, adding points was great, but getting stronger through sweat and effort? That hit different. Why not have both?
The sun rose outside, uncaring of anyone's plans. Riku started his daily training routine in the cave. Of course, with his new oni-level physical stats, this workout was a bit too easy. He'd need to crank up the intensity.
"Huff… huff… huff…" Riku controlled his breathing, sweating as he pushed himself. He wasn't a pro athlete, but he loved fitness and had some know-how.
But his workout was cut short when a familiar scent hit him—someone was near his temporary base.
"Is that… Kamado Tanjiro?" Riku froze, recognizing the scent. Then he sniffed again and frowned. "And that oni girl?"
What kind of combo was this? Wasn't the main character of Kimetsu no Yaiba a demon slayer? He rubbed his temples, digging through his spotty memory of the anime. He wasn't big on it, so most of what he knew was half-forgotten, like scraps from a mission report.
"Wait!" He clapped his hands. He'd found something in the memory junk pile. Kamado Tanjiro had a sister who'd been turned into an oni, always with a bamboo muzzle in her mouth!
"Hello? Is anyone in there?" Tanjiro's voice called from outside the cave.
"…" Riku froze in awkward silence. It hit him—the "oni girl" he'd tied up was probably Tanjiro's sister!
"Sorry, I'm coming in!" Tanjiro didn't wait for a reply. He sounded urgent, rushing into the cave with the "oni girl" in tow.
When Tanjiro stepped inside, Riku finally saw him face-to-face. Sure enough, the girl had a bamboo muzzle in her mouth.
"Look, if I said your family wasn't killed by me and I tied up your sister out of kindness, would you believe me?" Riku blurted out, trying to clear the air. He really didn't want to take the blame for this mess!
"I believe you," Tanjiro replied instantly, so straightforward it caught Riku off guard.
"Uh…" Riku blinked, thrown off. Then he noticed something odd. Tanjiro… didn't have a weapon?
"Please, Mr. Oni! Tell me how I can turn my sister back to normal! I'll do anything—even if it means you eat me!" Tanjiro bowed deeply, his voice raw with sincerity. He'd failed to protect his family, and if his life could save his sister, he'd pay that price without hesitation.
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