On a trip to the beach, Matora is taken out by a shady character, and things only get worse for our heroes from there. Kogarashi investigates the commotion only to discover his former master, Ouga Makyouin! She's arrived at Yuragi-sou to exorcise its resident ghost, and worse, she claims that Yuuna is actually an evil spirit hell-bent on destroying the planet!
Kogarashi has to think fast to prevent Yuuna from being exorcised forever-that is, if he still trusts her.