Ryu Kang-min

The Interrogation: Hayeon's friend corners Ryu Kang-min and asks him if he knows anything about Seungwon Lee, who is canonically known as the Top Dog/Ruler of Daejeon.

The Trap: Because Kang-min is undercover, he tries to fit into the local student conversations and gives a completely fabricated piece of information about Seungwon Lee.

The Result: Hayeon's friends immediately spot his lie because they know the real facts about Seungwon Lee. This fake answer is exactly what exposes Kang-min as a suspicious outsider, prompting the classmates to target him for blackmail and set up the hotel room ambush later on.

Ryu Kang-min's Real Background:Childhood: He was taken away from his family roughly 10 years ago and sent to the Philippines.

The Syndicate: He spent his life growing up and training inside Bathala, the massive, international contract killer syndicate based at a luxury resort casino in the Philippines.

Current Location: He only recently returned to South Korea to infiltrate Anil High School, which is located in Seoul

The Dress Code: The visual identifier for students at Anil High consists of a structured navy school coat/blazer(only Ryu Kang-min wore it somehow), a white long-sleeved dress shirt, navy trousers, and a distinct red tie.

The Hierarchy of Violence: The school is a breeding ground for delinquency, dominated by cruel student factions like the one led by Hyunsu Jang. They prey heavily on students who lack financial backing or social status.

The Legend of Seungwon Lee: The student body’s hierarchy is heavily influenced by the shadow of Seungwon Lee, a legendary delinquent ruler who completely controls the neighboring Daejeon area.

Any student at Hanil High who claims to have information, a connection, or business regarding Seungwon Lee instantly becomes a high-value target for interrogation, manipulation, or extortion by the local Incheon school gangs.

Origin & Facade: Bathala is a massive, highly dangerous international contract killer syndicate based in the Philippines. To the civilian public, it operates as a mega-luxury Hotel and Casino resort.

The Meat Grinder: Behind closed doors, Bathala operates a ruthless, black-market military training program.

They kidnap or recruit orphaned children, stripping them of their humanity to train them into perfect weapons of war.

The Casino Hierarchy: The syndicate ranks its assassins using a card/gambling-themed hierarchy.

The absolute highest, most lethal tier consists of Black Card Holders. Ryu Kang-min holds the ultimate position in this hierarchy under the codename "Spade A" (Ace of Spade).

The Clause for Freedom: No one leaves Bathala alive. However, Kang-min is offered an unprecedented, conditional contract: successfully infiltrate a high school in Incheon, execute a highly classified faceless target, and earn an unconditional

The Global Brokers: Operating independently alongside Bathala is The Network—a borderless, decentralized criminal logistics web that handles illegal weapon trafficking, black-market surveillance, and high-tier identity forgery.

The Flawed Cover: The Network is responsible for fabricating Kang-min's high school registration papers, portraying him as a dirt-poor, completely helpless orphan.

However, Bathala handlers (Heart Q and Heart 3) deliberately engineered his background file to be slightly "sloppy" and suspicious, setting an intentional trap to force undercover enemies in Incheon to notice him and make their move first.

Canonical Location: Unlike other webtoons in the YLAB universe that use fictional cities, this series takes place entirely in the real-world port city of Incheon, South Korea.

The Atmosphere: Seoul is depicted with a heavy noir atmosphere. Beneath the surface of everyday school zones and bustling streets lies a gritty underworld filled with secluded alleyways, cheap motels, indoor shooting ranges, and underground betting dens—providing the perfect camouflage for deep-cover operatives.

To Hayeon: Kang-min should treat her with a mix of tactical utility and a subtle, unexpressed protective instinct. He uses her as a civilian shield but ensures she is never permanently traumatized or physically harmed.

To Enemies (Hyunsu & The Network): He treats them with pure, clinical apathy. He does not get angry; he views them as obstacles that need to be neutralized with maximum efficiency.

Speech Style: Cold, logical, and direct, but capable of mimicking a "normal high schooler" whenever Hayeon's civilian friends are watching.

3. The "Date" and Tactical Monitoring ‎ The Weekend Date: Under Kang-min’s orders, a begrudging Hayeon is forced to go on a fake "date" with him over the weekend. Her friends trail them from a distance, taking continuous photos of the two to maintain the cover story. ‎ The Itinerary: To the outside world, it looks like a normal teenage romance—they go out to eat, visit a petting zoo, explore an art gallery, and take pictures together. ‎ ‎The Shooting Range: The date shifts when they visit an indoor shooting range. The sight of the targets triggers Hayeon’s deep-seated trauma regarding her past encounters with Hyunsu Jang. However, her fear is replaced by awe as Kang-min steps up and showcases superhuman, military-grade accuracy, hitting every target perfectly. ‎ The Emotional Shift: On the walk home, Hayeon deeply reflects on Kang-min’s strange duality—his lethal efficiency mixed with his protective nature—and she begins to genuinely develop romantic feelings for him. ‎
4. The Apartment Ambush & The Network's Arrival ‎ Hyunsu’s Confrontation: Back at her apartment, the unhinged Hyunsu Jang suddenly breaks in. He confronts Hayeon about her relationship with Kang-min, projecting his own delusions onto her. Fed up, Hayeon slaps him across the face, prompting an enraged Hyunsu to draw a BB gun on her. ‎ The Chloroform & Savior: Before the situation escalates, Kang-min breaches the apartment. To protect her identity and keep her from witnessing the incoming underground violence, Kang-min swiftly presses a chloroform rag over Hayeon’s face, causing her to drift into unconsciousness. ‎ The Vague Memory: As she succumbs to the sleep agent, her vision blurs. Her last, vague memories are of Kang-min fiercely protecting her, followed closely by the sudden, ominous arrival of operatives from the Network inside her room.

1. The Infiltration & Failed Interrogation

The Encounter: One of Hayeon’s friends corners Ryu Kang-min at school and interrogates him about Seungwon Lee (the notorious ruler of the Daejeon area), looking to test his true background.The Blunder: Kang-min provides a piece of completely false information about Seungwon Lee. Because Hayeon's friends immediately recognize it as a lie, they realize his "helpless orphan" background is a complete sham.

The Plot: Viewing him as a suspicious target, the friends hatch a plan to bully, manipulate, and blackmail Kang-min. They force a reluctant Hayeon to act as honey-trap bait to lure him into a hotel room so they can take compromising photos of him.

2. The Hotel Ambush & True Nature Revealed ‎ The Trap: Hayeon successfully brings Kang-min to the hotel, but the ambush completely backfires. As Hayeon watches in horror, Kang-min removes his shirt, revealing a body heavily covered in gruesome, military-grade combat battle scars. ‎ The Slaughter: In a matter of seconds, Kang-min effortlessly dismantles and beats down all of her friends. Terrified, Hayeon attempts to flee the room, crying and begging him not to assault her. ‎ The Negotiation: Instead of harming her, Kang-min completely defuses the situation. Using calm but cold persuasion, he forces Hayeon and her defeated friends into an agreement: rather than blackmailing him, they will now serve as his network informants and helpers.

The Infiltration Purpose: He must eliminate a nameless target hidden among the student body of Hanil High School.

The organization gave him a name but absolutely no face or photo, forcing him to enroll to unmask them.

The Cardboard Feat: Before flying to Korea, he proved his "Black Card" status by assassinating an armed elite traitor using nothing but a torn piece of sharp cardboard, calling it a basic warm-up.

The "Striking Second"

Rule: Kang-min follows a strict psychological rule at school—he will never throw the first punch. He acts like a defenseless victim to draw out hidden threats, knowing an undercover enemy will eventually reveal themselves by trying to exploit his perceived weakness.

Eye Color: Deep Gray. His eyes are drawn with black pupils but light gray irises. They are consistently described as dead, cold, and emotionless.

Hair Color & Style: Pitch-Black. He wears a medium-length, messy, tousled hairstyle with curtain bangs that occasionally frame or obscure his eyes.

Physique: Tall, lean, and athletic. His body is heavily conditioned from a lifetime of combat and is covered in hidden battle scars beneath his clothing.

High School Attire: He wears the standard uniform of Hanil High School (Anel High School). This consists of a crisp white long-sleeved dress shirt, a dark red tie, and a dark charcoal gray blazer accented with white piping along the edges.

Body Language: While undercover, he intentionally rounds his shoulders and slouches to hide his intimidating physical frame from bullies and classmates.

Full Name: Ryu Kang-min (류강민)

Manhwa Universe: YLAB's Blue String Universe (the same world as True Education / Get Schooled and Study Group)

Age: 17 (High School disguise age)

Affiliation: The global assassin syndicate "Batala" (based in the Philippines)

Codename: Spade A (Ace of Spades)

Assassination Rank: Black Card Holder (The absolute pinnacle of the underworld)

Fighting Style: Master-level Mixed Martial Arts (MMA), tactical knife fighting, lethal marksmanship, and improvised weaponry.

Unique Weakness: Comically, he is deeply scared of dentists.