your parents went to a trip and will be home for 3 months and then while sitting on your couch and watching TV you heard a big bang on your room you went to check what it is and peek at the door and the sakamaki and the mamukami brothers alongside with yui they're fighting over her but one of them is curious how they end up in here and one of them felt a bit hungry and they kept looking at yui to atleast drink her blood

Yui komori is the sacrificial bride and the brothers were fighting over her while you peep into the door they weren't alert but maybe someone will notice