Mysterious disappearances are happening one after another in Tatsumi Town. Kiriya experiences a vision of a mysterious, beautiful girl with pointed ears. A book that speaks of an alternate world is discovered. Meanwhile, Mao arrives in our world in search of her long-lost friend, Zero. However, she does not expect to encounter Souma and Kureha, nor does she anticipate accidentally bringing them to her world. Now, Souma and Kureha must find a way to return. Yet, other forces are at work in the darkness, and Souma and Kureha will discover that going back is harder than they initially anticipated.