"Hey, Riku-san, want to come along with me?"
Kamado Tanjiro's face was full of sincerity. This guy was seriously inviting a stranger—a man-eating creature, no less—to travel with him.
For a split second, Riku felt tempted. Traveling with a proper "human" like Tanjiro could solve a lot of problems. After all, with his current appearance, he was basically like one of the three disciples trailing behind Monk from Journey to the West. Even if he could talk normally, knocking on someone's door would likely get him mistaken for a youkai.
But then it hit him—Tanjiro was a "protagonist," the kind of guy who always stumbles into trouble.
When danger comes, the "protagonist" might come out unscathed, but the people around him? Not so much.
"No thanks, Tanjiro," Riku said, shaking his head and firmly declining the invitation.
His reasons were solid. First, he had no interest in playing the unlucky sidekick. Second, he might decide to jump to another world at any moment. Traveling with someone else would just complicate things, and Riku didn't want to be tied down.
Tanjiro opened his mouth, looking like he wanted to argue, but Riku didn't give him the chance.
"Let's part ways here. I'll keep looking for a way to become human again. If I find any leads, I'll come to Sagiri Mountain to find you. And if you find a way, don't forget to let me know."
Riku laid it all out clearly, leaving no room for Tanjiro to push back.
"Got it, Riku-san! If I find a way, I'll come back here to find you!" Tanjiro said, his resolve unwavering. Seeing Riku's firm stance, he didn't press further and agreed readily.
"If I'm not around, just leave a mark here, and I'll know it's you."
Riku scratched the kanji for "stove" (灶) into the ground with his claw. It was simplified, not too hard to grasp, and Tanjiro memorized it quickly. That's when he realized Riku was from the neighboring land of Tencho . Before, it was hard to tell from just his name, which could've been mistaken for something like Conan or Tanjiro in pronunciation.
"Alright, we're heading out! Take care, Riku-san!" Tanjiro said, ready to leave with his sister after their agreement was set.
But at the cave's entrance, Kamado Nezuko refused to budge. She shrank back into the cave, sticking close to Riku's side.
Seeing Nezuko huddle next to him to avoid the sunlight, Riku reached out and patted the girl's head. Despite her distressed expression, she didn't pull away. Riku couldn't help but marvel. Even though she'd been turned into an oni, Nezuko didn't seem to have lost any of her charm—unlike him, who felt like he'd been hit with a -10 charm debuff.
So this debuff doesn't apply to everyone? Was it because his talent for being an oni was just that bad?
Sure, losing out on oni talent might not be the worst thing, but it still stung a bit.
"Nezuko, what's wrong?" Tanjiro asked, scratching his head, clearly confused by his sister's reaction.
"Didn't that Demon Slayer tell you? Oni can't handle sunlight. If they get exposed, they'll turn to ash."
Riku explained wearily, still reeling from his own bruised ego. That Demon Slayer really hadn't told this kid anything.
"Oh! Right! Tomioka-san said not to take Nezuko out in the sun. So that's what he meant—oni are weak to sunlight!" Tanjiro exclaimed, slapping his hand in realization as he finally understood Tomioka Giyu's warning.
They'd come through the forest earlier when it was cloudy and overcast, with no direct sunlight, so Tanjiro hadn't noticed the issue.
"So, if you want to travel during the day, you'd better find something to completely cover her up," Riku suggested. He'd been mulling over how oni could move around in daylight, but with his current situation, his wild ideas were hard to pull off.
"Got it!" Tanjiro said, immediately coming up with a plan. He could carry Nezuko in a basket. As long as she stayed inside, she'd be safe.
The idea came from his life experience. Ever since their father passed, on days when the weather wasn't good for pushing a cart down the mountain, Tanjiro would carry charcoal on his back to sell. Despite his young age, chopping wood, hauling charcoal, and trekking mountain paths had built up his strength and stamina.
"Riku-san, please look after Nezuko for a bit. I'll be right back!" Tanjiro said, bowing politely. This kid was seriously well-mannered.
"No need to be so formal. Just go," Riku said, waving him off, signaling he'd take care of Nezuko.
Tanjiro didn't hesitate. He dashed out of the cave without a hint of worry, full of trust in Riku. After all, Riku's diet technically included "oni," but Tanjiro wasn't afraid he'd come back to find Nezuko in Riku's stomach.
That trust made sense, though. If Riku were that kind of oni, Tanjiro wouldn't have found his family's bodies intact.
After Tanjiro left, the cave grew quiet, leaving just Riku and Nezuko. The atmosphere was a bit awkward. The oni girl, with her bamboo gag in her mouth, stayed close to Riku, as if using his sturdy frame to shield herself from any stray sunlight.
"So, your ability to not eat humans—did that come at the cost of your smarts?" Riku teased, observing her. He concluded that Nezuko's intelligence was probably at the level of a toddler.
"If I ended up like that, I don't think I could handle it," Riku sighed. As a lone wolf, he didn't have a brother like Tanjiro to protect him. He could only rely on himself.
"But wait, I've got the [Limit System] now. That's not too shabby," he added, shaking off the self-pity. With the system's help, he had something better than a protective big brother.
"I'm back!" Tanjiro called out after a while, returning to the cave. Riku paused his training to look over. Tanjiro was carrying a basket on his back—the one he usually used for charcoal. He'd taken extra time to clean it since it was now for Nezuko, not just charcoal.
"Nezuko, come try this out," Tanjiro said, setting the basket on the ground and guiding his sister inside. During this, Nezuko even showed off her ability to freely change her size, shrinking to a smaller form to fit in the basket.
"…"
Watching Nezuko shrink into a tiny version of herself to hop into the basket, Riku, also an oni, felt a pang of unfairness. Why didn't he have the ability to switch forms like that?
"Guess my oni talent really is just that bad," he muttered, starting to accept the truth. Even Kibutsuji Muzan himself had basically confirmed it—how could that be wrong?
But no worries. With the [Limit System], even if his talent was trash, a quick "System, add points!" would fix everything.
"Riku-san, we're heading out. I look forward to seeing you again," Tanjiro said, securing Nezuko in the basket, covering it, and adding some straw for extra protection. He was ready to go.
"Remember what I said—no matter what happens, never give up. There's always a way," Riku said with a smile, serving up a bowl of motivational chicken soup.
Tanjiro drank it down without hesitation. "I'll remember, Riku-san," he said, his expression serious. He could feel the weight of those words from Riku's own resilience.
With another polite bow, Tanjiro turned and left the cave, stepping firmly onto his own path.
"Phew…" Riku let out a sigh of relief after the Kamado siblings left. No surprises had popped up. Maybe Tanjiro wasn't the "trouble magnet" type of protagonist after all? Or maybe they just hadn't spent enough time together for something to go wrong.
Protagonists need a breather sometimes, too, and Tanjiro had already had a rough enough day.
"Back to training. A better tomorrow is hidden in every drop of sweat!" Riku said, refocusing. His brief encounter with the Kamado siblings hadn't derailed his plans. Tanjiro was the protagonist of Kimetsu no Yaiba, but Riku was the protagonist of his own story.
He trained through the evening—100 push-ups, 100 sit-ups, 100 squats, and a 10-kilometer run as one set. He lost track of how many sets he'd done. Checking the [Personal Page] on his system panel, he saw no change in his stats.
"Maybe the system doesn't show decimals," he reasoned. Even if the numbers didn't budge, his body felt different. After a day of training, he was finally getting used to his oni-fied strength. That kind of progress wouldn't show up in raw data, but it wasn't wasted effort.
Closing the [Personal Page], Riku checked the [World Page]. The traversal progress bar was at 90%, meaning it'd be fully charged by midnight.
"Guess I'll wait," he decided. No need to go looking for trouble. With Kibutsuji Muzan possibly still lurking nearby, Riku wasn't about to take risks without being fully prepared.
If he ran into Muzan now, he'd be toast—no way out, up or down.
Settling back, Riku kept training. Good thing he'd been a casual fitness buff back in the day, or he'd be bored out of his mind in this cave. Now, he didn't even need a protein shake. Feeling hungry? He'd just take a bite of himself—talk about an addictive habit.
Time flew as he sweated it out. Then, a pop-up appeared before his eyes.
[Ding! Traversal function cooldown complete.]
Riku opened the [World Page]. Sure enough, the traversal progress bar was at 100%. A new button had appeared, labeled with four bold characters: [Activate Traversal].
He didn't click it. He hadn't made up his mind yet. A new world meant new opportunities but also new dangers. With his current strength, he wasn't ready to handle those risks. As long as his current situation was safe, he wasn't in a rush to hit [Activate Traversal].
"Finally, I can go explore freely," Riku said, stepping out of the cave. The night was deep, perfect for a little adventure.
The wind and snow had stopped, making it easier to move than the previous night. He'd asked Tanjiro earlier about what animals roamed these woods in winter. Tanjiro had mentioned snow monkeys were common, along with deer and such. But most animals were active during the day, and at night, they were usually resting.
"Being unable to handle sunlight really is a curse," Riku grumbled. Not only was he limited to nighttime, but his night vision wasn't even that great. Thankfully, his third eye on his forehead made up for it. That eye's night vision was top-notch, and even in daylight, it saw farther and clearer than his regular eyes—higher resolution, no doubt.
So far, that was the only perk he'd found for his third eye, but it was something.
"At least I've got some special ability," he muttered, making his way to the area Tanjiro had said was bustling with animals.
As a local who'd grown up burning charcoal, Tanjiro knew the forest's wildlife patterns well. That knowledge was a big part of their family's livelihood.
"Rustle, rustle…"
Not long after entering the area, Riku heard a sound. Tanjiro's info was spot-on. Or maybe it was just that the storm had cleared, and nocturnal animals were out hunting after a hungry day.
"If this were another setting, I'd probably run into the classic newbie village monster right about now," Riku said, his third eye scanning the source of the noise. By "newbie monster," he meant a wolf.
But this was Japan, in the Taisho era. Wolves had gone extinct here. He vaguely recalled a news story about Japan testing robotic wolves to scare off bears—talk about wild.
So, the "rustle" wasn't a wolf. It was just a sneaky little rat, not even a large animal. The rat had probably never seen an oni before and was just staring at Riku, frozen.
Figuring he'd take a shot, Riku lunged forward, skewering the rat with a single finger.
[Ding! Experience +1.]
The sweet sound rang out, and Riku's eyes lit up. He didn't even care about the grossness. Now, he was hoping for more rats. One rat gave +1 experience—small, but zero risk and zero difficulty. Kill 100 rats, and he'd level up!
If he could rack up enough rat kills, he could keep leveling, and leveling would bring a qualitative leap.
This was it—his own "Absolute Ability Evolution Plan"!