The Boy I Loved Became the Jaded Emperor 1 (manga)

The Boy I Loved Became the Jaded Emperor manga volume 1 features story by Bekio and art by Ii Oshikawa.

As a young boy, Prince Alexei was rescued from certain death by a friendly monster, and the two of them spent blissful days in the forest. But tragedy struck when Alexei's royal destiny caught up with him again. Now a young man, Alexei has taken the throne, becoming Emperor and vowing revenge. Little does he know, the creature who saved him has been reborn as the daughter of a duke--a taciturn young lady with a secret. When fate throws them together at the imperial court, will they recognize each other, or will their jaded pasts keep them apart?