Gensokyo faces sudden disturbance as 'Scarlet Mist' spreads once again.To Reimu Hakurei, this peculiar phenomenon resembled something familiar. 'Is this that vampire's doing?', she thought to herself. There was only one choice: head to the Scarlet Devil Mansion, and find out the true cause of the disturbance. ......but this time, the way to the mansion was a little different from usual.