There's a rumor going around about the urban legend known as "Kudan." They say that it takes the form of a woman in mourning dress, her face covered by a black veil, her right severed at the wrist... They say that those who lay eyes on her are doomed to have misfortune befall them within seven days...

Feelings start to bud between student Sakuya Kudan and culinary teacher Touko Shima after coincidence brings them into one another's orbit. However, their peaceful everyday life is abruptly shattered when Touko sees Kudan, the harbinger of calamity. The hours tick down as Sakuya rushes find a way to combat the curse, and her search brings her to the academy's Occult Research Club and its president, Koto Ashinaki. Now she must face off against the unknown in order to protect the people she loves...