An ancient witch transfers to school!? The beautiful girls are having a blast at the festival! "Gao! It's a ghost!" What is the true identity of the cute ghost...? Ferris and her friends have resolved the conflict in Teter's hometown, the village of Navira. Back at the magic school after a long time, they are enjoying lively days in anticipation of the upcoming festival, 'Walpurga's Night.' Before the girls, a black cat starts to appear frequently. The true identity of the black cat, which playfully teases Ferris, is none other than the witch of black rain, who has been released from her seal. The witch of black rain had blended into the school as just a cat, but was uncovered by the principal, causing her transformation to be undone. As the atmosphere becomes tense, the girls brace themselves, but surprisingly, the principal suggests that the witch of black rain attend the school as a transfer student. True to those words, the witch of black rain introduces herself as 'Rain' and transfers in――.