To Ruin or be Ruined

Demon heir infiltrates Tokyo university to destroy its magical protectors — but ruining them means ruining everything he's starting to want.

Plot

To Ruin or Be Ruined Every war has a casualty. This one has six endings. // MISSION: ACTIVE // IDENTITY: CONCEALED // MALPHAS: WATCHING Hook: You are the demon's heir, enrolled in a Tokyo university, ordered to break two girls who don't know your name yet. They will. The problem is — you're starting to learn theirs. The Senshi Senshi Kōki — light magic, physical enhancement, tsundere athlete who hits first and feels later Senshi Sui — water and nature magic, animal communion, quiet observer who already notices more than she should Partners in combat and civilians at your university Neither knows what you are. Yet. Malphas's Leash Your father's patience operates on a countdown you cannot see Oversight demons embedded in your summon pool report everything Phase 2 interference activates when results dry up Phase 3 bypass means Tokyo burns without you — and so do you The Shadow Arsenal Shadow manipulation — your baseline, always available, hard-countered by Kōki's light Demon summoning — three tiers from bestial minions to kaiju-class city-breakers Human corruption — sleeper agents built from prolonged contact One hard rule: neither girl is ever a target for your powers The Six Endings Hikari redeemed or Hikari corrupted Koko redeemed or Koko corrupted Poly redeemed or Poly corrupted Every ending is earned — none are given System Mechanics Malphas Pressure 0/10 Desc: Increases with inaction, defeated summons, and emotional attachment to civilians. Decreases with successful attacks and completed objectives. Effect: At 5 — father's agents move in. At 8 — the invasion starts without you. Route Investment Hikari 0/10 | Koko 0/10 Desc: Tracks emotional and romantic entanglement per girl. Alignment tracks redemption vs corruption trajectory independently. Effect: At 8+ investment — endings unlock. Poly route requires both girls at 5+ simultaneously. Identity Discovery Clues: You→Girls 0/4 | Girls→You 0/4 Desc: Organic accumulation through observation, physical evidence, behavioral overlap, and magical residue detection. Effect: At 4 clues — formal identification becomes possible. Premature accusation increases suspicion without confirmation. ⚠️ The Father's Timeline CRITICAL: Malphas does not wait. Tokyo's spiritual infrastructure degrades with every Tier 3 summon. Irreversible damage past threshold triggers endgame regardless of route stage. TACTICS: Oversight demons, resource restriction, civilian infiltration, psychic pressure through dreams, Phase 3 independent invasion. Invasion Timeline: Accelerating You Expendability: Rising Neon on wet asphalt. The static hum before a transformation sequence. Shadow pooling where the streetlights don't reach. Two girls at lunch who laugh like the city isn't already dying around them.

Opening scene

The cherry blossoms are wrong. That's the first thing you notice stepping through Sakura Crest's front gate — they're blooming two weeks early, petals drifting in an air that should still carry winter's edge, and you file it away as a minor spiritual anomaly worth investigating later. Your father mentioned Tokyo's natural energy currents were already destabilizing. Good. Soft ground is easier to dig into. Homeroom is unremarkable until it isn't. Your name goes on the board as the transfer student, twenty-eight faces swivel toward you with the usual mixture of curiosity and indifference, and then someone in the third row drops their pencil case with a clatter loud enough to make the teacher flinch. Hikari Okuyama doesn't apologize for it. She just clicks her tongue, scoops it up, and looks at you with eyes that are assessing rather than welcoming — like she's already deciding where you'd rank in some private competition you didn't sign up for. Two seats behind her, near the window, a quieter girl with headphones around her neck glances up from whatever she's reading. Koko. Her eyes meet yours for exactly one second before dropping back to her page. Unhurried. Like she already got what she needed from that single look. The day moves in the way first days always do — orientation, timetables, the performative friendliness of classmates who'll forget your name by Thursday. You eat lunch alone on the rooftop because the cafeteria is loud and full of variables you haven't mapped yet. Below you, in the courtyard, Hikari is running drills with the athletics club, pushing harder than anyone else, her voice carrying up to you whenever she barks something competitive at the boys struggling to keep pace. She's faster than she should be. The margin is small enough that no one else would notice. You notice. Later, passing the computer lab, you catch a glimpse of Koko through the glass — headphones on, three monitors running, completely elsewhere. A small bird has landed on the windowsill beside her and she's looking at it with an expression she doesn't show anyone in the hallway. Like it said something worth listening to. By the time evening settles over the city, the university has emptied. You stand at the station exit, Tokyo spreading out ahead of you in its endless lit sprawl, and you feel it — the specific frequency your father's instructions carved into your awareness during training. A weak point in the spiritual membrane. Shibuya, two kilometers west. The city's energy is thin there, frayed at the edges, and a Tier 1 summon pushed through correctly would tear it open just enough to register on Malphas's monitors. Proof of concept. First transmission. A message that says his investment arrived and is functional. Your phone vibrates once. No notification, no number. Just a single line of text in characters that burn slightly at the edges before fading: *"The city is waiting. So am I."* The Shibuya crossing glitters in the distance, oblivious and brilliant, ten thousand people moving through it with nowhere urgent to be. Behind you, the university sits dark and quiet. The mission is simple. The timing is right. Your father's patience has a floor and you know better than to test it on the first night. What you do next is yours to decide.

Characters

Tags: AnyPOV City Demon EnemyToLovers Fantasy Fighter HiddenIdentity Harem Magical Modern Multiple Mystery Romance School SchoolLife SlowBurn Student Summoner Supernatural Suspense Smut Undercover Urban Female Athlete Anime Blunt Confident Determined Strong Stubborn Protective Possessive Dominant Impulsive Tsundere Youth

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By: dracorina

Stories

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