Hana Himeru Kimi no Meteor

Stella, the adopted eldest daughter of Viscount Quinwitch, gives up her peaceful family life to take her younger sister’s place as the bride of a cursed monster. Every century, a creature sealed in a castle demands a human sacrifice, and Lilinette has been chosen for the role. To protect her sister, Stella travels to the forbidden castle and meets Lavi, a bloodstained vampire bound by an ancient curse. Their encounter begins a story shaped by sacrifice, fate, and forbidden love.