The Tyrant Who Loved Lies

Pouring Rain. Gleaming Dark Light. With the not her own identical but similar face with her twin sister.
And the man that wants her sister, instead of her. Not the older sister but the younger one.
"Are you the older or the younger one?"
When he asks, the older sister Ja Myeong answered in a daze.
"I am the younger sister Hye Myeong."
This signals a prelude to a tragic. She lies to the emperor whom she has secretly adored. The day when her younger sister was appointed Queen, Ja Myeong makes up her mind to become a Priestess, in order to expiate her wrong. Nonetheless, her one-time lie does not let Ja Myeong go but continues to weigh upon her.
"Have you ever told a lie?"

(From the official website)

Original Novel:
Naver Series

Original Webtoon:
Naver Webtoon, Naver Series

Official Translations:
Japanese