Ep 4. E 4

Taito and Himea run inside the school building to escape the red rain that is lethal to the touch. Once inside, Himea's body is possessed by some other being. Taito faces off against the invisible enemy to keep his promise to Himea. As Himea's love for Taito and Taito's desire to protect Himea come together, the wheels of fate begin to turn.