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Sengoku Heat I: The Ghost and the Demon King

Summary:

In 2026, Soma Kurogane built skyscrapers. In 1559, he had to engineer his own survival against the Demon King.

Soma Kurogane is a brilliant 24-year-old structural engineer, a young genius who accelerated his education and career at an early age and whose life is defined by cold logic, strict corporate hierarchies, and flawless mathematics. But when a devastating car accident plunges his SUV into the freezing Kiso River, Soma is rescued by a mysterious figure and wakes up four centuries in the past. Stranded in the blood-soaked Sengoku period with nothing but his wits and a single waterproof suitcase of modern tech, Soma is captured by Japan’s most terrifying warlord: Oda Nobunaga. To avoid execution, Soma must prove his worth. Armed with 21st-century logistics, he treats the brutal feudal era like a hostile corporate takeover. Caught in a highly charged, suffocating game of power, submission, and biology, Soma's cold logic begins to melt under the Warlord's blistering heat. As enemy spies infiltrate the domain and assassination plots loom in the dark, Soma must balance the crushing weight of a warlord's obsession with the treacherous desires of his own captive flesh.

Notes:

Welcome to Sengoku Heat I

This story is a blend of timeslip, historical fiction, sci-fi fantasy, erotica, dark romance, and a dash of light comedy.

I want to focus on the struggles of the character in his timeslip journey, incorporating his skills and knowledge to stay alive. The narrative explores the dangerous, highly possessive bond he forms with the legendary Oda Nobunaga, as well as the shifting, complex devotions he discovers as he fights to find a true sanctuary in a blood-soaked century. Aside from this, as a history lover, I will try my best to authentically show the culture, politics, and brutal way of life during the Warring States Period of Japan.

🔞 Content Warning: Explicit MM Erotica, Dark Romance, Reverse Harem & Love Triangle Dynamics. Please be advised that this novel contains highly explicit and graphic sexual descriptions. The erotica in this story is not merely gratuitous; the intense power exchange, heavy dominance, and sexual situations are seamlessly blended with the plot. They act as a crucial catalyst for character development, mirroring both the toxic, high-stakes possession of Nobunaga, and the desperate, grounding need for sanctuary.

Note to Readers: While Book 1 focuses heavily on Soma’s intense, possessive bond with Lord Nobunaga, please be advised that the relationship dynamics in this series are not static. As the war escalates in future books, prepare for shifting loyalties, complex emotional choices, and evolving romantic dynamics.

⚠️ Author’s Note: This novel is a work of fiction. While inspired by the real figures, politics, and setting of the Sengoku Jidai, the author has taken significant creative liberties with historical events, timelines, and character actions for dramatic and narrative purposes. All romantic relationships, private interactions, and dialogue are entirely products of the author's imagination.

I hope you enjoy reading my story. Comments on my story are highly appreciated; they are my greatest motivation to continue writing and expanding this world!

Chapter 1: The River of Time

Chapter Text


📺 Sengoku Heat — Novel Series Opening Edit

I created a short video edit so you can see what Soma, Kenta, and Nobunaga look like in my mind! Think of it like the opening title sequence to a BL drama series. 🎬✨

▶️ CLICK TO WATCH: Sengoku Heat Opening Edit
(Plays in a clean, ad-free full-screen player)


 


Location: Gifu-Aichi border, Japan

Current Date/Time: 2026 • Late Summer • Evening

Rubber wiper blades dragged across the curved glass of the windshield. They squeaked against the slick glass, failing to clear the view. The heavy summer rain smeared the road into gray streaks, bending the headlight beams. Torrents of water hammered the roof of the SUV in a steady, deafening pound.

The heavy metal frame of the truck shook under the downpour. The storm funneled straight down the narrow mountain pass, turning the asphalt hill into a fast, running river.

Soma Kurogane kept his eyes locked on the road ahead. Through his thin glasses, he watched the concrete retaining walls lining the cliffside to his left.

The sprayed concrete facing was failing. The drainage holes drilled into the wall were vomiting thick, brown mud. Hairline cracks spiderwebbed across the gray surface, weeping dirty water.

The dirt above the cliff wall was shifting under the massive load of rainwater. The weight of the trapped water was backing up hard behind the concrete barrier.

Soma tracked the spacing of the steel tiebacks bolted into the wall. The stress plates were bowing outward. The ground anchors holding the hillside back were ready to snap. The mountain was coming apart.

Sweat ran down his neck. A cold drop soaked into the collar of his white t-shirt.

The heater blasted dry air from the dashboard vents, but the windows were still fogging up at the edges. Hours of driving clawed at his shoulders. Tension locked down his lower back, an old ache left over from years of university rugby scrums and winter climbs.

He forced himself to take slow, steady breaths. He pulled air through his nose, counted to four, held it, and let it out slow through his mouth to drop his pulse.

His heart rate slowed down. His tight grip on the leather steering wheel relaxed just a bit.

He shifted his weight in the driver's seat. The heavy wool and stiff leather sleeves of his varsity jacket bunched over his chest. Beneath his stiff raw denim jeans, he was glad he’d worn smooth underwear that wouldn't chafe after eight hours straight in the seat.

Black coffee sloshed over the plastic lid of a paper cup in the console. The bitter, roasted smell mixed with the dry scent of the cardboard cup holder.

The back seat was packed to the roof. Taped moving boxes jammed against the rear windows, shifting slightly with the sway of the vehicle. A hard-shell Samsonite luggage rested on the floorboards, wedged tight behind the passenger seat. Everything he owned sat compressed into this cabin.

The phone buzzed in the cup holder. The OLED screen cast a pale, sharp glare across his face, illuminating the off-center fringe of his dark hair. He pressed the speaker button on the dashboard console, keeping his left hand firmly at the ten o'clock position on the wheel.

"Boss." Kenji’s rough voice scratched through the vehicle's audio system, competing with the drumming rain.

"What is it?" Soma asked.

"The steel supply convoy for the Hokkaido naval base is delayed. The heavy rains are washing out the lower mountain access roads. The transport trucks are backed up at the weigh station. The drivers are refusing to move until the storm passes."

A fresh fissure cracked across the asphalt ahead. Water bubbled up from the fault line in the road, washing loose gravel down the slope.

"We need to pour the foundation concrete before the coastal trenches flood," Soma said. "Divert the onsite crews. Cover the primary pouring sections with the heavy industrial tarps. Tie them down to the outer rebar stakes."

"The wind is kicking up on the coast. The tarps are turning into sails."

"Double the tie-downs," Soma commanded. "If that wet concrete takes on this much rainwater, it dilutes the aggregate ratio. It ruins the chemical hydration process. The cure will fail. When those naval destroyers hit the dry docks, the weakened stone will shatter under the kinetic impact."

"Understood. What about the lower utility trenches? We have exposed metal down there. The water table is rising fast."

"Keep the diesel pumps running on maximum output. Clear the mud off the exposed steel rebar grids. Rust breaks metal faster than impact. Water and dirt cause rapid oxidation. I want this base built strong enough to stop the sea, Kenji. Not succumb to it."

"Yes, boss. I’ll reassign the scaffolding crew to tarp duty. We are running low on heavy-duty ratchets."

"Pull them from the secondary staging area. Strip the equipment from the dry storage sheds if you have to. Protect the foundation pour at all costs."

"Done. I'm heading down to the dig site now." Kenji paused, the sound of static and heavy machinery bleeding through the microphone. "Check the backup generators for the pumps. If the grid drops, we lose the trenches in ten minutes."

"Copy that. Be careful driving in this storm. The news is reporting mudslides on Route 19. There were several reports of accidents on the news."

"I'm managing."

The call clicked off. The cabin returned to the isolated, rhythmic drumming of the rain against the steel roof.

A second later, a voice message notification pinged through the speakers. Haruka.

Soma extended a stiff finger and tapped the dashboard screen. His older sister’s sharp, fast-paced voice filled the cabin.

🔊 Voice Message Playback

"Soma, do not forget you have a scheduled fitting next month for the autumn catalog. I may work in fashion, but I am not your personal manager. The agency called me three times today. Stop making me coordinate your schedule."

[Soma exhaled. A loose strand of hair fell forward, tickling his forehead. He ignored it.]

"One more thing... I opened your luggage before you left. I swapped out your basics. I added a few new custom underwear sets. The fabric is an experimental silk-elastane blend. It breathes better under heavy studio lighting."

[A bright laugh crackled through the speaker, distorted by the white noise caused by signal loss.]

"Make sure to show the agents that big package of yours, little brother. I wish women...and men can see your face. It's so sad that your contract states that they will only show your torso and hip area."

[The line crackled for a moment, and her voice changed. She stopped talking like a fast corporate boss.]

"But seriously. Manage your corporate engineering work and the modeling sideline. You can't oversee naval base construction in Hokkaido and shoot fashion campaigns in Tokyo without burning out. The human body has limits, even yours. You sleep four hours a night. Let's catch up once your done with your project. Drive safe, little brother."

The message ended.

Soma stared at the wet road. "I hope these sets are more comfortable this time," he muttered. He glanced up at the rearview mirror. His dark eyes bypassed the rain lashing against the rear glass and locked onto the black hard-shell suitcase wedged securely in the backseat.

It sat heavy and unmoving against the cardboard boxes. Inside lay his rolled building blueprints, his drafting computer, his steel-toed site boots, and whatever extra clothes Haruka had forced into the side pockets before he left.

"Just get to the highway," he muttered, his voice barely carrying over the drumbeat of the storm.

He tightened his grip on the leather steering wheel, his knuckles turning white under the strain as the road banked sharply to the left. The decline steepened.

Then, the steering wheel went completely light in his hands.

The sickening sensation of floating hit his chest as the rear tires lost their grip on the wet asphalt. The heavy truck became a dead weight, its back end swinging violently toward the cliff edge, where a rusted ribbon of guardrail looked incredibly thin against the dark drop.

Soma lifted his right foot completely off the gas. He kept his foot away from the brake, letting the engine's weight drag the truck down to try to catch a grip on the road.

Suddenly, a blinding flash of white and purple light scorched the road.

In the brief glare, a massive dead cedar tree split at its base with a deep, cracking roar that shook the air. The root system was torn clean out of the wet mud, and the thick trunk collapsed downward, crashing directly across the pass in a shower of splintered wood and wet branches.

Soma slammed his sneaker onto the brake pedal, shoving it flat against the floorboard.

The pedal pulsed violently, shaking the sole of his shoe as the pads grabbed the wet metal. But the flooded road offered no grip at all. The tires locked, and the truck slid forward over the sheet of water, spinning completely sideways.

Soma locked his elbows, bracing his arms against the wheel as the headlights swept off the road, cutting uselessly into the empty, black air beyond the cliff.

Metal screamed.

The side of the truck smashed into the rusted guardrail, shearing the bolts holding the steel to the concrete posts. The metal buckled and tore, and the heavy vehicle broke through the line, snapping the steel support poles like dry twigs.

The SUV tipped.

The front wheels dropped off the concrete edge. Soma slammed hard against his shoulder strap, the belt locking up and pinning his collarbone to the seat as the heavy metal cage of the truck fell into the dark.

The car hit the Kiso River like a brick wall.

The impact shook the entire frame, shattering the windshield into a white web of cracked safety glass. The steering wheel airbag fired with a loud pop, the nylon bag punching outward and hitting Soma’s chest so hard it knocked every bit of air right out of his lungs.

His head snapped back against the seat, his wire-frame glasses flying off his face and disappearing into the dark footwell.

Cold, muddy river water shot through the broken windshield and the bent door edges, blasting into the cab. The water soaked through his wool jacket, his t-shirt, and his stiff denim jeans in a second.

The cold hit his chest like a hammer. The water was freezing.

His skin went tight, his chest locking up from the shock. The river water rose fast, swallowing his waist, then his ribs, as the dashboard lights flickered, sparked blue and yellow, and went dead.

Pitch blackness took the car.

Panic hit his chest, his lungs burning for air, but he forced himself to stay completely still.

The river current was pushing hard against the outside of the doors. With thousands of pounds of water pressure holding them shut, trying to push them open now was useless. He had to wait. He needed the cab to fill up completely so the water weight inside would match the outside.

The water reached his neck, rising over his chin. He tilted his head back against the ceiling, sucking in one last breath before the water took his face.

The cab went completely under. The deafening roar of the storm vanished, replaced by the heavy, muffled rushing sound of the river.

He opened his eyes, the dirty water stinging them. He saw nothing but black.

Soma reached blindly through the rushing water, his thumb finding the cold metal of the seatbelt release. He pressed hard until the buckle clicked.

He let go of the wheel, letting the water push his body back. He twisted his shoulders, squeezing his large frame between the front seats into the flooded rear cabin.

His numb fingers brushed the cardboard boxes. They were turning to mush in the water. He pushed past them until his hand hit the hard plastic of his suitcase. He dragged his fingers along the shell until he found the thick rubber handle, locking his grip tight.

Soma planted his wet sneakers flat against the steering column. He pulled his knees into his chest and kicked the buckled driver-side door with everything he had.

The bent hinges popped.

The door broke outward, the heavy current catching the metal panel and tearing it back. The undertow sucked Soma out of the cab, and he tumbled into the Kiso River.

The freezing water tasted foul, full of mud, pine needles, and grit, mixed with the copper taste of blood from a cut on his lip. The current grabbed his body, spinning him end over end until he had no idea which way was up.

His chest spasmed, begging for air.

His right hand stayed locked on the suitcase handle in a death grip. The hard-shell case was sealed tight, acting like a float in the water. The heavy box dragged his wet wool jacket upward, pulling his head toward the surface and keeping him away from the jagged rocks on the riverbed below.

The heavy roar of the river began to fade, turning into a sharp, thin ringing deep in his ears. The freezing water pressed hard against his eyelids.

His fingers went completely numb, his grip going dead as his mind slipped into the quiet black.