Marika, a depressed girl, sat in a corner sketching quietly. There was no joy in her eyes, only a faint peace hidden in her art. Suddenly, everything around her began to change. She was pulled into a strange place—an endless castle. Before she could understand, she had already entered the **world of demon slayers**.

She fell hard on the ground; pain shot through her body, especially her waist. As she struggled to get up, fear tightened in her chest. Just then, someone placed a hand on her shoulder.
“AAA! Let me go!!!” Marika screamed.

She froze when she saw the boy standing before her.
“M-Muichiro?”

The boy smiled faintly. “No, idiot. I’m not Muichiro. I’m Haruchiro Rikuya.”

Marika blinked. “But… you look exactly like Muichiro.”
Haruchiro shrugged. “Fans have already imagined an adult and taller version of Muichiro. I’m no exception.”

Annoyed, Marika sighed. The two began walking together. Suddenly, a crow appeared and announced, *“You two have a mission in this forest!”*

Marika shivered. “Mission? But I’m not a demon slayer!”
Haruchiro smirked. “Come on, this is the demon slayer world. Our OCs are demon slayers.”
“No, I—”
Before she could finish, Haruchiro grabbed her hand. “We’ll do it together!”

As they walked further, Haruchiro asked, “By the way, what’s your name?”
The girl hesitated, then said softly, “Marika.”
A gentle smile appeared on Haruchiro’s lips.

But their calm moment shattered when a demon attacked. A fierce battle broke out.

The next morning, Marika opened her eyes and found Mitsuri sitting beside her.
“MITSURI!!!!! You’re so beautiful, so cute, I’M YOUR BIGGEST FAN!!!”

Mitsuri giggled. “Finally, you’re awake! I heard you became a demon slayer without any training. Then let me train you!”

Meanwhile, Haruchiro woke up to Inosuke punching him.
“Ahhh! What was that, Inosuke!!”
“How do you know my name!?” Inosuke shouted.
Haruchiro only asked desperately, “Where’s that girl? Is she okay?”

Just then, Muichiro appeared and dragged him away. “You’ll train with me!”

A few days later, Haruchiro returned and saw Marika gazing at Giyuu with hearts in her eyes. Jealousy burned inside him. He pulled her away.
“Let me go!!!” she cried.

At that moment, the master **Kagaya Ubuyashiki** called for a meeting.
“There’s a village where only married men are disappearing. You must investigate.”

So Shinobu and Giyuu, along with Haruchiro and Marika disguised as a married couple, went to the village. Each pair stayed separately, pretending to live as husband and wife.

That night, in one room—
“I WILL NEVER SLEEP WITH YOU!!! YOU BETTER SLEEP ON THE FLOOR!” Marika shouted.
Haruchiro calmly replied, “I don’t mind sleeping with you. It’s your problem, so you sleep on the floor.”

Suddenly, they heard noises outside. The two quickly pretended to be asleep together.

But the door creaked open—a female demon entered. Another battle began.

After the fight, Haruchiro lay badly wounded. His head rested on Marika’s lap as tears streamed down her face.
“Please don’t die… I beg—”
Suddenly, his eyes opened with joy. “You’re begging!?”
Angry, Marika smacked him again and again.

Days passed. Sometimes they read books together, sometimes Marika refused to share food while Haruchiro looked at her with eyes full of love. At times, he brought wildflowers and sat beside her.

Yet Marika’s eyes always drifted toward Giyuu.
“Oh my god, Giyuu-san looks so hot~” she whispered with a blush.

Haruchiro’s expression darkened with jealousy.
“What happened?” Marika asked, startled.

Suddenly, he grabbed her shoulders.
“Don’t you understand how I feel when you talk about other men? Don’t you know I want to be the only one you like? Don’t you know I love you!?”

Marika stared at him in shock. Then she whispered, “I love you too.”
Haruchiro froze, speechless.

But the next moment, Marika added, “But Giyuu-san is still handsome.”
Boiling with rage, Haruchiro chased after her.