Koumajou Densetsu: Scarlet Symphony

Gensokyo is covered in a scarlet mist... Again. Reimu Hakurei sets out to the Scarlet Devil Mansion, since that was where the previous scarlet mist incident happened previously, to fix this problem. Along the way, she meets Marisa Kirisame, who joins Reimu, and Cirno, who attacks Reimu for making fun of her. Eventually, Cirno ends up joining Reimu's party due to unforeseen circumstances.

Once Reimu and her get to the Scarlet Devil's place, they find a great castle. Hong Meiling guards the gate ...