Once, there was a timid but considerate young girl. Becoming an exorcist amidst her family's expectations, she grew to be exceptionally skilled.

Then, a younger sister was born.

The sister could not see supernatural anomalies properly, but she was loved by everyone for her bright and social personality. The older sister was not jealous. Instead, she was happy, and worrying about the dark path of an exorcist's life, she began to teach the younger girl what she knew.

(During a lesson) Sister: I have a question! Harin: What is it? Sister: How can you... (expectant look) Sister: ...be so terrible at teaching?! Harin: (Expression turning serious) You, come here. Sister: Ah, just kidding, just kidding!! I'm sorry! Harin: I'll have to fix that attitude of yours with a reversal spell...! Sister: (Runs away)

Eventually, the day of the final lesson arrived.

The sister felt that Harin's lesson was a bit strange today. Something was there. Something was happening. But she didn't know what. I don't know. I don't know. "Tell me." "Please." Something red on the floor— "What are you doing?" "Is the final lesson always like this?"

"I..." "think this is for the best."

The girl, with a blank expression, pointed a kitchen knife at her sister—

---

The older sister spoke to the blood-stained younger sister. "Now go. Right now. Get out of my sight."

Having finished her final lesson like that, the younger sister returned home, her heart covered in wounds. But it was strange. Her mother and father were nowhere to be seen. She searched the whole house, but they weren't there. She asked the household staff, but they all simply replied that they didn't know.

"Why are you doing this to me..."

The moment she uttered those words, the world began to appear in black and white. She had truly gained the ability to see [Anomalies]. Suddenly, she remembered. 'Sister said that if something looks black, it's an evil spirit. White is a normal person or object, and gray is a barrier or a spell.'

Once during a lesson, her sister had said something meaningful. 'The ability to see [Anomalies]... it can be acquired later, but it's too early for you to handle. Still, if by any chance you do see them... you'd better steel your heart. Because...'

She couldn't remember the rest, but she didn't even want to think about it now. Sister. Now, just thinking of that name was terrifying.

Slowly, dragging her bloodied body, the sister walked. So far, everything was white. The house, the place where she took lessons with her sister—all were white. It wasn't because of an [Anomaly]. She was sure of that. At least, right now, in her eyes.

Then, her sister appeared before her with a deep smile. The younger sister instinctively stepped back. However, strangely, the household members were all there together. Something was wrong. 'Everyone is clearly white...?'

Thinking that, she looked down at her own body...

Gray and white were mixed together.

The sister screamed in shock, crying out that she was scared. No one answered. The sister panicked. Then, she happened to check the type of spell placed upon her...

Reversal Spell

'What?' She couldn't remember much else given the situation, but she clearly remembered the Reversal Spell. Back then, in the lesson... Wait. Wait a minute. Hold on. If it's a Reversal Spell....

Then the fact that everything looks white means%@^@×><×@&@&^@%@^#$@@@/#:@_@#:#:##^#^&#^#%^#^×<×>[×[@@>×<×^×&×

When she woke up, the spell had been lifted and the household members were all dead. The sister felt a sense of dissonance. The wooden sword in her hand felt strangely heavy. A sickening, sticky sensation came from the handle. The sister slowly looked at the wooden sword. And...

She finally understood what her sister had meant. 'Get out of here.' That was... the last thing her sister had said with her own mind while being possessed by an evil spirit. The sister collapsed and wailed for a long time.

And reaching the present day, the younger sister—no, Seo Harin—became a capable exorcist.