I Pretended to Be the Demon Lord's White Moonlight

I transmigrated, and the task my boss sent me to do was uncover the truth behind the death of the previous transmigrator, Lan Siyu. So he disguised me to look like Lan Siyu and sent me undercover to the side of a Demon Lord who kills people at the slightest provocation.

The Demon Lord recognized at a glance that I wasn't her, because Lan Siyu was the one he treasured most.

Later, my investigation revealed that the Demon Lord wanted to destroy the world, and my boss told me to stop him.

I sized up my own scrawny body. Why should I? Am I supposed to rely on my looks?

Boss: Smile more. Your luck can't be that bad.

Me: ...Oh, go to hell!

In the end, the world wasn't destroyed.

Because she loved this world, and he loved her deeply.

Short story, around 30,000 to 40,000 words

Theme: Love cannot be replaced