Maria's Curse summary:

From Momo Chidori, the author of Ake no Tobari. Comes a new action romantic one-shot manga.A long time ago, a demon was sealed inside a giant crystals. Now, the demon has broken free. It's up to Maria to seal the demon once again with the help of her boyfriend Kiyotsugu. But Kiyotsugu have to die first to Maria's curse.This manga is part of Ganma! app One-Shot tournament.