Yumemiru Hanazono

From FCTranslations]:

When Momoe visited her old school, she remembered an event occurred there when she was still a student. Twenty years ago, rumors said there's one man who came to the girls' dorm by night, search for his very own targets, and steal their soul. To find out the truth, Momoe, who teamed up with three other friends, is determined to find this intruder. One rainy night, she found a naked young man near the church, and it turned out he has a lot of connections with the one Momoe is searching for......