Renji Yamamoto was a simple, straightforward middle school boy. He had no enemies, no grand ambitions.
All he wanted was a peaceful environment, and his life was going quite well—until the day everything began to change.
"RENJI, YOU CAN'T BE THIS SLOW!!" Mizuki yelled.
Renji was rushing to get ready so fast it looked like a storm had passed through his room.
Mizuki smacked him lightly on the head before heading out. "Clean the room when you're back."
Renji looked at her face and shivered—her terrifying expression only made her seem even scarier.
Mizuki shouted again, "Hurry up! You've already taken two hours!"
Renji muttered, "Do you even remember how many times you've told me to 'hurry up'?"
Mizuki then took Renji to Hotaru Yamamoto's house to talk about enrolling him at Eryndralis Academy.
Hotaru Yamamoto was Renji's uncle, the elder brother of Haruka Yamamoto, and currently a senior instructor at the academy. Just before stepping inside, Renji muttered, "I still haven't eaten anything yet…"
Mizuki blinked, then scratched her cheek. "Oh—sorry. I'm a spirit, so I don't need to eat… I guess I completely forgot about you." Renji sighed. "You guess?"
Mizuki reached into her magic inventory and pulled out a soft bun and a small bottle of water, handing them to Renji. "Here. Eat this for now."
Renji took them without complaint—the growl from his stomach was louder than his pride. After Renji finished eating, they stepped into Hotaru's house.
Hotaru's eyes immediately narrowed at the sight of Mizuki. "Who are you? And what business do you have here?"
Without a word, Mizuki reached into her magic inventory and drew out a dagger—its blade unmistakably belonged to Haruka Yamamoto.
Hotaru's expression hardened. "So… you're Mizuki. That means…" His gaze shifted to Renji. "This boy… is my nephew, Renji." Renji couldn't make sense of what was going on.
Hotaru turned to Mizuki, his tone sharp. "You haven't told him anything yet?"
Mizuki shook her head. "I've told him… but not about your part in all this." Hotaru adjusted his glasses and looked straight at Renji. "Aside from the hair color, everything about you is just like your father."
Renji stayed silent, unsure how to respond.
Mizuki finally spoke. "He's your father's elder brother—your uncle." "Yeah and you're only standi here because your father was trapped to a damn f*kind world without magic." Hotaru replied. Renji asked, "But why didn't my father ever return to this world? If what you're saying is true, and he was a hero… shouldn't he have come back?"
Mizuki looked down slightly. "He would have, if he could. But…"
Hotaru sighed. "Heh—coming from that world to here was sort of your father's fate. But after he arrived, he bumped into your mother on the street—and at that moment, he fell for her."
Hotaru's voice grew heavier. "That one mistake changed everything. You still can't even use magic properly, yet your father… he was the third strongest human in all of mankind's history."
Renji lowered his head, unsure what to say.
Mizuki stepped forward. "Mr. Hotaru, it's your duty now to teach Renji—to help him grow stronger. He's far more powerful than you can imagine… maybe even stronger than Mr. Haruka himself." Hotaru stayed quiet. Mizuki said, "Oof, that's enough talking! Start Renji's training already — hurry up! We don't have much time left!"
Hotaru snapped, "Silence! You're nothing but the spirit of a dead girl — a soul barely clinging to this world through a magical stone. Don't forget your place."
Renji looked down, his eyes growing sharp. "You may be my uncle, but you can't talk to Mizuki like that."
Before he could say another word, Mizuki stopped him. "Enough, Renji. He's your father's elder brother — show some respect when you speak to him."
Hotaru chuckled. "Haha, you really are just like your father — always too soft when it comes to girls. Anyway, I've got a pile of academy paperwork waiting for me, so I need to go."
Then, as he reached for the door, he suddenly turned to Renji. "And you — before you can enroll, you'll have to go through basic training. Don't take my words too seriously; I only said that out of work stress."
Mizuki asked, "But who's going to train him? You?"
Hotaru shook his head. "No, you will. Just teach him the basics — simple magic and sword skills, the kind we usually start with for six or seven-year-olds."
Before Mizuki could respond, Hotaru suddenly teleported, appearing atop a tall tree nearby.
"Good grief… what a reckless kid," he muttered. "That boy's mana source isn't even fully unsealed yet, and still—just from his aura—it feels like he could swallow me whole. He might be even more dangerous than Haruka ever was." Mizuki said, "Oh no… I completely forgot!"
Renji looked at her, puzzled. "Forgot what?"
Mizuki turned toward him with a serious face. "We still haven't completed a single quest from the Adventurers Guild."
Renji said, "So what? What happens if we don't?"
Mizuki sighed. "If you don't complete at least three quests a month, your guild card will expire. And there are only two days left in this month."
Renji frowned. "But I can't even swing a stick properly yet—let alone a sword!"
Mizuki waved her hand dismissively. "Eeeh, relax! We're not going monster hunting right away. We just need to finish a few small, easy quests — that'll be enough."
Renji asked, "But what about my training then?"
Mizuki crossed her arms and sighed. "Hmm… no big deal. I'll train you as much as I can while we're out there. We'll just combine both — questing and training."
---
Then the two of them headed to the guild. As soon as they entered, Rika spotted them and called out, "Hey, Renji! Over here!"
When Renji walked up to her, Rika smiled slyly. "So, you're finally here to take some quests, huh? Good timing — I've got a few beginner-level ones for you."
She handed Renji four quest papers. The first one was to collect some poisonous mushrooms from the nearby forest, the second to gather a few medical herbs, the third to repair the roof of an old monastery, and the fourth — to slay ten goblins.
Before Renji could even say anything, Mizuki quickly snatched the first three quests and said, "We'll take these!"
Rika said, "No one else wanted to take these quests anyway. If you guys handle them, it'll honestly be a relief."
Mizuki chuckled. "Hehe, yeah — Renji's not good at magic or swordsmanship yet."
Rika sighed. "That's… quite concerning."
Closing her eyes for a moment, Rika added, "Listen, simple gathering quests like these aren't always available at the guild. So you two might have to take on a monster hunt soon—"
But when she opened her eyes again, Renji and Mizuki were already walking out the gate.
"Hey! Where are you going without listening to me?!" Rika puffed her cheeks in frustration — her irritated yet flustered expression somehow made her look even cuter.
The other adventurers in the guild all turned to stare at her, smiling quietly.
Flustered, Rika's face turned bright red as she stammered, "E–Excuse me! Sorry for shouting!" before quickly running back into her office room.
---
Renji asked, "Mizuki, which quest are we doing first?"
Mizuki replied, "Let's start by repairing the monastery roof. Once we're done there, we'll head straight into the forest to finish the other quests."
Within fifteen minutes, they reached the monastery. Renji approached a nearby caretaker and asked politely, "Could you please show us which part of the roof needs fixing?"
The caretaker pointed toward the damaged section, and before Renji could even process it, Mizuki raised her hand and cast a powerful spell. In less than twenty seconds, the entire roof was perfectly restored to its original state.
The caretaker asked, "Ah, are you two from the Adventurers Guild?"
"Yes," Mizuki replied with a small smile.
"Oh, thank you so much! We don't have any strong mages around here, and we couldn't afford a new roof either. I submitted that request to the guild almost a month and a half ago," the caretaker said with relief.
Mizuki smiled gently. "Oh, no problem at all. It feels nice to help people sometimes."
Meanwhile, Renji was thinking to himself, I barely understood what just happened… she finished everything before I could even blink!
"Renji, come on," Mizuki said, turning to him. "Let's go finish the rest of the quests."
The caretaker waved at them with a warm smile. "Good luck, and may blessings follow your journey!"
Renji and Mizuki nodded politely before heading out toward their next destination.
Around 1 and a half hours Renji and Mizuki made their way toward the forest called Crimsonwood — the same forest where Renji had run earlier that morning. Mizuki said, "Renji, listen. We might have to go deeper into the forest, so be careful. This place is filled with terrifying monsters."
The Crimsonwood Forest was located about half a mile northeast of the town. Renji and Mizuki quickly collected the poisonous mushrooms, but the medical herbs were found much deeper inside the forest.
"Um, Mizuki, is it really safe to go this deep?" Renji asked.
"No tension," Mizuki replied, "I'm here to protect you."
Renji said nothing. As they went further, the scenery around them kept repeating. Renji thought, What's happening? We're walking, but we're not getting anywhere.
After a while, Mizuki noticed it too. They both stopped and held each other's hands tightly. From the distance, Renji saw an unfamiliar figure approaching.
The person's hair was white. Their eyes and nose were completely covered by long hair. There was a black mark on the right cheek. The body was tall but looked thin and fragile.
Renji didn't understand anything. He looked toward Mizuki. Mizuki's eyes widened as she stared at the figure — her hands trembling.
Renji said, "Is that a woman?"
"N–No... That c–can't be... That's..."
Before Mizuki could do anything, the trees around them began sinking into the ground as if the soil had turned into molten lava. The sky turned dark red. Suddenly, three wild demon wolves appeared in front of them. The wolves started rushing toward them to attack.
Renji began trembling in fear. "M–Mizuki... What's happening?"
Mizuki didn't respond. The wolves ran straight through them — like they weren't real, like holograms.
The surroundings grew darker, but the mysterious figure was still clearly visible. Renji looked beside him — Mizuki was gone.
The figure suddenly appeared right in front of him. Before Renji could react, the figure shoved its hand straight into Renji's abdomen. Renji screamed in pain, blood dripping from his mouth.
Then hot lava started bursting from all around him. It felt like he had fallen into hell itself. Suddenly, countless skeletons began running toward him. They were all SS-rank. Renji was terrified.
When he regained his senses, he saw himself lying on Mizuki's lap while she was healing him.
"Mizuki, what's happening?" he asked weakly.
"I don't know," Mizuki said. "That thing... it's definitely a demon... Not just any demon — probably a Hell General."
Renji looked confused. "H–Hell... what?"
"Not just a Hell General," said the voice of the figure, "I am an Elite Hell General."
But the figure couldn't be seen anywhere.
"This isn't the time to talk," Mizuki said. "We need to escape now."
The figure suddenly appeared again in front of Renji and thrust its hand into his abdomen once more.
"This demon is too strong," Mizuki said. "I'll defe—"
Before she could finish, the figure moved a few steps back and said, "Enough talking." Then he glared at Renji. Seeing the terrified expression on Renji's face, he said, "I don't understand what Lord Drazeth saw in you. You're not even worth killing a mosquito."
He launched a heavy punch toward Renji, but Mizuki barely managed to block it.
"Oh, so this girl's guarding you?" the figure said mockingly. "Then I'll just kill her first."
He punched again, but since Mizuki was a spirit, the attack passed right through her.
"Oh... a spirit user," the figure sneered. "So this fragile creature relies on the soul of the dead. How amusing."
Then he used a skill — searching through Renji's body for Mizuki's Spirit Stone, also known as the Spirit Core.
"Hmm... interesting," he murmured. "You're carrying a spirit core inside your own heart."
He cast a spell — Mizuki started fading away, her body slowly turning into light.
"Renji, run!" Mizuki shouted as she disappeared.
Her entire form turned into a small white light orb that entered Renji's chest.
Renji screamed, "Mizuki... no!"
The demon chuckled, "Don't worry. I didn't destroy her completely — just sealed her inside you."
Renji went crazy, trembling, his mind racing for a way to escape.
That figure struck — a wooden spike pierced his left side, and a powerful blow shattered the bone in his right leg. Renji screamed in agony, struggling to rise.
"The name is Ozyrith… and you better never forget it," the figure hissed.
"Enough games for today," Ozyrith added, smirking. "The fun's over." With that, he vanished into thin air, and the forest returned to its normal state. The illusions dissipated completely.
Shivering, Renji stumbled outside, but as soon as he started to move towards the exit he collapsed to the ground.