Looking for a shounen-ai manga

I forgot to add this to my reading list and now can't find it.

I remember it's a shounen-ai manga with either a fantasy or supernatural touch.

Story goes like this.

Two high School boys lives are connected by fate because of what their ancestors did. One ancestor, though male, still served as a Miko in order guard a sealed box. He befriended a village boy, fell in love with each other so he kinda lost focus on his task and the evil in the box was set lose. His descendants were cursed to be haunted by said evil. His friend/lover took it upon himself to share said curse so his descendants were also haunted. Then now in the current generation, the two guys are trying to survive 12 misfortunes (failure leads to death). They have a flower shape mark indicating the misfortunes. When they successfully conquer one, one of the petals disappear.

Thanks in advance.