From Shoujo Crusade:

Rumors have been going around about certain killings in a certain place. One night, Mito wanders into this certain place and encounters two suspicious people who speak of demons who come out at night.

The next day in school, she discovers the two of them has transferred into her school and class! Will she get caught up in what looks like shady business that happens after dark!?

Included one-shots: Okotoba desu ga, Oujo-sama; Hime no Kotonoha